Rugby World Cup: The ref debate

It's been a long time between posts - busy work periods, lack of inspiration, lack of news stories (well, that's not entirely true!), but pick the excuse.  Apologies for the long break. I'm back with a viewpoint on rugby - probably not the topic of interest for most of you reading this in the USA, but as our national sport in SA, felt compelled to put it out there!  I'm planning a series on fatigue, probably as a series of short video posts in the coming week, so hopefully that breaks the silence on sports science!  Join us soon!  And for those who followed the Rugby World Cup, congratulations to New Zealand.  Some thoughts on the refereeing below!


Rugby World Cup: New Zealand's drought ends and rugby's referee problem

So 24 years of waiting is over for New Zealand, who beat France 8-7 in a pulsating and perhaps unexpectedly competitive Rugby World Cup Final today.  It may have been the lowest scoring final ever played, but it was suspenseful and adventurous, certainly more than the previous two finals.  France produced a performance worthy of the showpiece match of the tournament, having come into it with two losses and the anticipation of a blowout victory to New Zealand.  Rather, it was France who played the adventurous rugby, and only some ineffectiveness in attack and New Zealand's resolute defending prevented them from winning their first title.  

Instead, New Zealand won their second, but it was significant in that they have been, for the most part, the best team going into each of the six World Cup tournaments, sometimes by a large margin.  Having failed to win the World Cup on five occasions despite being the favorites had earned New Zealand the tag of "chokers", a team that peaked between World Cups but failed to deliver when it mattered.  Two of those famous defeats came at the hands of France (in 1999 and 2007) and so when this French team stood firm and began to control the match following a second half try that brought the score back to 8-7, a blanket of anxiety settled over Eden Park in Auckland.  

Choking vs panic

There were times when New Zealand appeared close to panic in this final - they were flustered, made unforced errors, chose poor tactical options and generally seemed to be hanging on and defending a one-point lead with desire rather than application.  At this point, it seemed to me that had New Zealand NOT won this World Cup, it would have been because of panic, rather than choking (an explanation that is just too convenient to use, and unfairly earned, not only by NZ rugby by also by SA cricket).  Their composure deserted them, though the injury to their flyhalf, which meant that they played most of the final with a fourth choice pivot, certainly influenced their tactical approach.  As did their lead, and they seemed more concerned with defending the one-point advantage than playing proactively, which set the final 30 minutes up as France with the ball, New Zealand without it.

For an explanation of how choking differs from panic, and why a team that loses a match is not necessarily choking, read this piece by Malcolm Gladwell.  I've never really been fond of simply throwing out the excuse of "chokers" every time the more favored team loses - sometimes you are just outplayed or out-thought by a team who are better than you on the day.  The margins in international sport are so small that this can happen fairly easily, and it's too simple to say "New Zealand choked", when in fact, France may have simply been unbeatable on a given day, as was the case in 1999.  For a comparable case in tennis, Federer's loss to Tsonga in Wimbledon earlier this year is the best I can think of - sometimes, however great you are, the other team/player just rises to a level that no one would match, and it's your bad fortune to be there at the time!  

The influence of the referee in rugby

However, the tactical and technical nature of the game is not what I want to focus on in this post - that is something that rugby websites around the world will do enough of (see this example for a match report).  

Instead, I thought I would give some of my thoughts on a topic that follows every rugby match, and that is the debate and criticism of the referee.  The reality is that the referee in a rugby match has become incredibly influential in determining how the game is played.  The result is that rugby has a growing credibility problem, where every match threatens to degenerate into objections about the performance of the referee, rather than assessment of the relative performances of its players.  Whenever the result on the scoreboard can be dismissed as being the result of someone's opinion or bias, there is a problem.  

And this has happened in virtually every close match in the 2011 Rugby World Cup, which will be remembered not solely for the on-field performances, but for weak referee performances, some of which have been questionable, some outright poor.  The most controversial of these probably came in the Quarter-final, where Australia beat South Africa 11-9 in a match that was later alleged to have been "bent" as part of the condemnation on the performance of referee Bryce Lawrence (more on my views of that allegation later)

Rugby presents a unique challenge in that the referee is required to make a specific decision about a contested tackle almost 200 times a match (once every 30 seconds), and this decision is multi-dimensional, instantaneous and open to interpretation.  As a result, these decisions (and there are so many of them) influence the game to the extent that accusation, criticism and allegation are inevitable.   It's part of sport, certainly, but rugby seems more prone to accusations that "the ref helped ABC win" than any other sport.  The problem is that from this point, it's a short journey to allegations of fixing, corruption and cheating, when the problem may be simple incompetence or interpretation of the tackle rules of the sport.  Either way, the credibility of a result is called into question.

This situation exists because so much of the contest in rugby revolves around competing for the ball after a tackle, in the breakdown contest.  The attacking team needs to recycle possession quickly, whereas the defending team are at worst trying to slow it down to re-organize in defence, at best trying to win the ball on the ground.  The result is a huge contest, the outcome of which goes a considerable distance towards determining the match result, but which is itself determined by how the referee interprets how both sets of players test the boundaries of the law (because this is what players will do, understandably - it's like football players trying to play close to the offside line)

A unique situation?

I cannot think of another sport where the interpretation of the rule by an official so clearly influences the way that teams play the match.  In football (soccer), the most contentious decisions are those when a penalty appeal is made, offsides is ruled, or when foul-play is adjudged.   They are fairly clear-cut, and far less frequent than in rugby.  And certainly, they can influence matches in a big way - I'm not downplaying how significant a referee decision can be.  In the NFL, decisions can be similarly significant, but usually involve clear transgressions of rules.  Tennis, there's no influence, particularly now that television replays are used.  And similarly, cricket umpires are often criticized and single decisions can be very influential, but with TV assistance, the incidence of these has certainly come down.  If there is a sport that I'm missing, please let me know.

The rugby situation - too much interpretation

Rugby is different - the most contentious decision in rugby is one that is made on average twice a minute (five times a minute if you use ball in play time rather than total time), and it influences the next minute, rather than being a decision in isolation.  Consider that a typical match has about 170 rucks (or contests for the ball in a tackle) , and you realize that there are probably 100 decisions (because not all are contested the same way) where the referee must interpret, in a split second, a dizzying array of laws, and where each decision has implications for what follows.  

Different referees have a different sequence or approach to the decision, but they must judge, more or less in order: how the tackler interacts with the tackled player, when the tackle actually occurs, that the tackler releases the tackled player, that the tackled player releases the ball, when the ruck is formed, that players arriving to join the ruck remain on their feet, and that they join from the correct position and do not seal the ball off to prevent the contest.  Add in that there are often multiple tacklers, so the referee has to decide who the tackler is, and you appreciate that within half a second, there's a lot to judge.  Then the next problem is that many times, four or five things happen more or less simultaneously, and so it really is a judgment call.

Ultimately, what the decision comes down to is a) assigning roles to the involved players, and b) deciding on the order in which events occur - every tackle has similar events, and the job of the referee is to sort through the order in which they occur,  and if he sees a different order to you or I, then his decision will be accordingly different.  And this is precisely what happens to make these decisions so contentious.

I've been fortunate enough to work with the SA Sevens team for the last three seasons, and at every tournament, the IRB Head of Referees, all the coaches and technical staff of competing teams, and all the referees have a sit-down meeting a few days before the tournament starts.  The meetings involve discussion around how the referees have been instructed to officiate and usually include clips of tackles and rucks from previous tournaments.  Now bear in mind that this is Sevens, where the contest involves fewer players and with less congestion than you'd see in 15s, and then consider that even so, there rarely agreement in these meetings.  The situation in 15-man rugby is of course even more complex (though the tackle contest may be more significant in 7s, but that's for another discussion!)

For each clip, one coach will point to the tackler, another to the tackled player, another to the arriving player, another to the offside line, each one pointing out a different possible transgression PER RUCK!  Mostly, it boils to disagreement about the order in which events happen, and which player should be entitled to do what.  Eventually, even in slow-motion, it takes consensus or a swing vote to sort through the order of decisions that a referee must make.  Even then, it's often a 50-50 call as to whether a player released the tackled player or the ball and so on (if you are reading this without much knowledge of rugby and you're confused at how complex it sounds, well, that's exactly the point!)

A general approach to the decision and its implications

The reality is that rugby, by design, prioritizes the contest for the ball on the ground, and therefore the spotlight falls squarely on the man who must judge whether players are transgressing those laws.  Simple on paper - there is a very distinct set of rules governing the tackle.  But here's the problem - the rules may be clear, but the judgment of them is not.  So much is open to interpretation, and it is interpretation that happens in an instant, while on the run.  The result is that a match can very, very easily look 'influenced' by the referee, who generally speaking, can take one of two extreme approaches to how they cut through this organized chaos to make a decision.  Call it "conservative" vs "liberal" decision-making, but at its simplest, a referee is going to lean one of two ways.

The first approach is to over-police the contest (the conservative).  The result is that the referee will appear to punish legitimate contesting for the ball, and will reward penalties frequently, forcing players to back right off, killing the contest for the ball.  This favors the team in possession.  Alternatively, the referee can under-police the breakdowns (liberal), and allow much more to go unpenalized.  

Importantly, when this happens, the result is that the defending team will usually be favoured, because the referee will fail to prevent them from slowing the ball down, and slowing it down creates a disproportionate advantage.  I believe this is what happened in the South Africa - Australia match, where the rucks were highly contested and too much was allowed on the ground.  The result is that the defending team is advantaged.  But, significantly, the problem in that particular match is that the defending team was mostly Australia.

The stats reveal this - South Africa had 131 rucks, compared to Australia's 44.  That is, for every one opportunity for South Africa to contest and slow down Australian ball, there were three chances for Australia to do so.  So, by allowing too much contesting, the referee effectively gave Australia three times as many chances to push the limits of what was legal (and some would say exceed those limits).

When one team is as dominant as this (in terms of possession), and the more liberal referee is making the extreme "decision" to under-police and allow more, then it will always appear that he is deliberately biased.  The reality is that if the possession was equal, and if both teams have the same number of rucks, then nobody would really notice the referee because BOTH TEAMS would get away with slowing the other team's ball down!  You'd get a very messy match, but the liberal referee would be far more "anonymous" because his leaning affects both sides equally.

Instead, this match was one-sided, and South Africa seemed to be on the receiving end of an unfair performance.  I do think that Lawrence was poor, and I do think that his poor performance affected SA more, but it wasn't deliberate.  And as for match-fixing?  Not based on decisions that didn't go our way, no.  Rather, I think that the referee was poor and didn't do enough to control the rucks, but my point is that this may be because he was either instructed to allow the contest, and "over-applied" the instruction, or he just has a natural inclination to be liberal towards the contest.

In the case of Bryce Lawrence, it would not surprise me if he was told to allow a contest for the ball, because earlier in the tournament (in the Aus v Ireland match), he was criticized for penalizing Australia TOO MUCH at the breakdown.  I strongly suspect that what happened next is that he was asked to be a little slower on the whistle, and he erred on the other extreme, and didn't do enough.  In the end, it appeared that South Africa were hard done by, but as I have said, that's more because whenever one team dominates play, an error like Lawrence's appears to favour the team without the ball (Australia).

Analyzing referees - navigating with a broken compass

It may not surprise you to learn, for example, that many international teams now attempt to analyze referee trends, so that they can attempt to guess whether a given referee is likely to decide one way or the other.  At the most basic level, for example, you can look at whether a particular referee tends to award a penalty to the attacking team or the defending team to get an idea of that referee's "in-built bias".  This partly reveals whether that referee's priority in assessing the breakdown is whether the attacking team player releases the ball (penalty against the attacking team) or whether the tackler releases the player (defending team).  You can then go further to see whether the referee is more or less lenient on the tackler or the tackled player and the arriving supporting players from either team.

The problem with this approach is two-fold.  First, it's subjective.  When analysing clips, you have to judge not only what the referee does decide, but what he does not.  This means you have to make a call yourself, and this brings us back to the point about disputable situations, especially because on TV, you don't see what the referee does.  

The second problem, more significant, is that the referees, in my experience anyway, are too unpredictable to code in this way.  They are influenced by individual players and teams, and they change their approach too often, probably because they are very susceptible to suggestion and to the instructions coming down at them from their superiors. 

For example, we tried this in the Sevens setup,but it was a futile quest, because the referees changed their approach too often.  We worked out that what was happening was that the IRB were evaluating the referees and providing feedback on their performances (which is a good thing, of course), but this feedback was influencing the way that referee approached their next match.  The result was that for each referee, if you plotted a graph showing how they made decisions, it would look like a zig-zag curve of mountain peaks and valleys - one week they leaned one way, the next week they went the other.  And so trying to pre-empt how they would decide was like navigating with a broken compass.  

Yet again, what this showed is the "unstable" nature of the decision-making process.  Again, 170 decisions per match, each one in a fraction of a second at speed, with five or more variables to assess is going to introduce some "interpretation", and the problem is that this can lean one way or another very easily.

Emotion - the inherent bias when working backwards

The other factor in all this is that emotion and passion are such significant influencers of how we interpret this watching on television.  Fans (and even neutral spectators) have an inherent bias (it's what makes them fans!) and the result is that when they assess a referee performance, they exist in a world of black and white - the referee is either right or wrong.  Unfortunately for rugby, the decision is rarely black and white.  It is grey, because of the previously mentioned decisions around judging the order in which events occur, and who does what in the tackle, and so there is always conflict between what fans see and what is actually happening on the ground.

Consider an example from football (soccer):  A player scores a goal but is offside when he received the pass.  The referee/assistant see this, and the goal is correctly disallowed.  On first viewing, a fan who feels that his team has been robbed can make all manner of accusations including match-fixing and bias, but a replay will prove him wrong in most cases.  Similarly, in tennis, the ball is either in or out, and in the Hawkeye era, there's little dispute over those calls.  NFL, there are debatable calls (pass interference, roughing the passer etc), but they're much less frequent and different in nature to the ongoing, continuous rugby tackle calls.  

Rugby, however, has a much more subjective decision happening 170 times a match, and that's why I laboured the point about how "grey" the decision-making process can be earlier in this post.  The end result is that people who watch matches can make the logic mistake of working backwards.  They then interpret their observations to fit their theory, and of course their desired theory is that their team must win!  

It's a lot like bent science, in fact, in that you start out with the finding already "known" (in a fan's mind, there is only one team that can win - they "know" the result before the match!).  Then you have a series of "experiments", also known as the tackle situation, where the outcome of each must be known too.  The entire match is an observed experiment, and unwittingly, people mix emotion with interpretation and they will come up with accusations of bias because their observation will always fit their model.  This is the danger of looking for proof of what you already believe, because you will always succeed at finding it!

Don't trust the passionate perception

I made this mistake myself when working with the Sevens team.  Every single decision was "wrong" as long as it went against our team!  Such is the desire to win, that I stood on the sidelines and could not believe that a penalty should not be awarded to us.  We lose the ball, it could only be because the other team cheated, and the referee missed it!  

Only in the cold light of day, often the next morning, sitting in the hotel lobby, did I have the opportunity to review the match, sometimes to talk to the referee and he would explain what he was seeing as he made the call, and then it became much clearer to me that what was "obvious" to me was in fact "obvious" in exactly the other direction!  I was wrong, pure and simple.  But at the time I could not see that I was looking at it incorrectly.  I learned to have a deep mistrust of my own perceptions in those emotional, stressful situations, and learned instead to wait, hold the opinion and rather decide when removed from the passion and emotion.  It was a valuable lesson.  

Sometimes, of course, the referees did make mistakes - more than once, I still believe we were wrongly judged and that it cost matches.  Sometimes, referees even admitted it, and apologized.  But we have also been the beneficiaries of the decisions, and that's the result of rugby's tackle rule.  It certainly needs to be fixed, but this was a difficult lesson to learn, but an important one.

The reality is that fans need to step away from the emotion, and if they did, they may, in the case of South Africa anyway, recognize a few other reasons why it was New Zealand, and not us, lifting that trophy in Auckland yesterday.

The solution - analysis and a scorecard

As for the solution, my bias as a scientist is to measure and analyse, so that's where I'd look for rugby's problem.   And transparency would help - no one really knows what the IRB does with referees - they are accused of being a "protected species", which may not necessarily be a bad thing, but I do feel that some more open discussion would help.  At the moment, it's all left to the media, and in this day and age, the "media" now includes social networking, and so the public WILL have their say, and they are rarely going to be diplomatic in the absence of information.  Rather control the perception by making some information available  (it's a lot like the Caster Semenya case - the secrecy around her testing and treatment only fueled the flames and allowed people to make up the "truth".  And that version is always worse than the real truth).

And for rugby, the solution to me is that the performance of referees needs to be evaluated more transparently.  A panel of independent officials could analyze matches, producing a report on the match.  This report could analyze every single one of the 200 decisions a referee has to make in a match.  How many of the 200 were incorrect?  20? 30?  And of those 30, how many were clear, conclusive errors, and how many were interpretive calls?  One has to build in this human interpretation element, because it would be wrong to think that one can accurately judge off TV when the referee is 5m away from the decision he is making.

And of those conclusive errors, do they favor one team?  If you find for example that 30 decisions out of 200 are wrong, and 90% of them go against one team, then you have some weight behind accusations of bias or fixing.  But until that kind of evaluation is done, people speculate, and speculation is almost always worse than the truth.

Especially when the passions of die-hard fans are involved.  Just ask any referee...

Ross

Training, talent, 10000 hours and the genes

Genes and performances: Why some are more equal than others

The genetic influence on exercise performance is dizzyingly complex.  So complex that my best efforts to explain how genes may impact on the science of performance will fail to capture just how enormously complex the various interactions are.  It is so complex that despite the best efforts of scientists to find "the performance genes", they have failed.  This has been interpreted in some quarters to mean that these genes don't exist, that genes are unimportant and that training counts for all - nothing could be further from the truth.  The reality is simply that they're too numerous, with too small an influence, and too complex to find...for now.

However, having previously discussed the 'holes' in the theory that success in sport can be explained by deliberate practice, it's important to consider the genetic component.  When I presented evidence that showed, for example, that only 28% of variance in darts performance could be explained by 15 years of practice time, then it begs the question of where the remaining 72% lies?  When you consider that some athletes are able to become world-class within 12 months of taking up a sport, whereas others slog for a lifetime to stay mediocre, part of the reason may lie in the genes.

And of course, this is enormously complex.  So let me say this upfront today:  The science of success is about the coming together of dozens, perhaps hundreds of factors.  Practice, quality coaching and time spent learning are clearly key factors - this is why you get "hot-beds" of performance, exceptional athletes from anywhere that opportunities exist - the impact of training on performance is large enough that it can help to offset potential differences in innate abilities.  Can it turn anyone into a world-beater?  My opinion is no, but this doesn't decrease the value of the training.

Equally valuable, I believe (and some of the early evidence is below) are genes or innate ability, and this is what has been downplayed in the popular media.  It is not wrong to suggest that practice is crucial and that elite performers do many hours of training. But it is incomplete. And sometimes, incorrect, when you promote one at the expense of the other - training and genes are additive, not exclusive.  So when Ericsson writes in his 2009 paper that:

"distinctive characteristics of exceptional performers are the result of adaptations to extended and intense practice activities that selectively activate dormant genes that are contained within all healthy individuals’ DNA” (Ericsson et al 2009)

it must be challenged on the basis that the science may not necessarily support this.

And to help complete the picture, we look at genes - that is the context of this post.

As mentioned, I have recently written two review articles on this subject - one will be published in Dialogues in Cardiovascular Medicine to co-incide with next year's London Olympic Games, the other will hopefully be published in 2012.  My co-author, Prof Malcolm Collins, is a geneticist, and I owe a debt of gratitude to him for some of the genetic concepts I explain in this post.  So let's look at genes and performance.

The most powerful genetic influence of performance is...

At the risk of starting with the blindingly obvious, the first key point to make is that the single biggest impact made by any factor on sports performance is genetic, and it is biological sex.  Before people react negatively to that statement, please don't view it is a statement of superiority or inferiority - it is simply a fact, and is the very reason we recognize (and embrace) separate categories for competition.  Ask the following question:  If we did NOT recognize that men and women should compete in separate categories in most sports, how many women would be competitive?

Take marathon running - Paula Radcliffe holds one of the most respected records in athletics with her marathon world record.  That performance, easily the best ever by a woman, would have ranked her 473rd in an "open" world list in 2009 alone.  That is, 472 men were faster than this time in a single year.  In history, the time was ranked 3,205th, and that was in 2009 - it's now probably close to 4000th.

This gap exists in all athletic disciplines ranging from 100m to 100km - a 10 to 15% difference between the best men and women is seen across the board.  Of course, the differences may be smaller in other sports - skill-based activities that are not heavily influenced by size, strength, heart or lung volume, hemoglobin content etc may be more competitive.  But the difference still exists (would you back Serena or Venus Williams against Federer or Nadal?), and the result is that if we competed in only one category, no major sporting prize would ever be won by a female competitor.

This is the very reason that we recognize separate competitions - they enable competitiveness.  And the point is that this characteristic, biological sex, is entirely genetically determined.  There are of course cases where the neat binary system we create is skewed by intersex conditions, and we debate and discuss cases like Caster Semenya's endlessly.  In those instances, there is a mismatch between genetic and anatomical sex, such that the chromosomes no longer determine the biology.  However, genetics is entirely responsible for male and female characteristics, and this has an enormous impact on performance.

The question is, if genes exert such an enormous impact on the entire organism, are there similar genetic differences within each grouping, and do these affect various systems (muscle, heart, physiology) in the same way?

Genetic complexity - height as an example of complexity

The next illustration is height.  It's well established that height is a highly heritable characteristic. In fact, 80% of height has been linked to a number of genes (it's called a polygenic trait because many genes influence it), with the remaining 20% being down to environment and diet.

The key about height is that as "simple" a characteristic as it is, it is still impossible to identify all the specific genes and the contributions they make to it, how they interact.  And here, it's important to understand the approaches to the problem.  One can look for single genes - they are called "candidate genes" - that account for the biggest impact in height.  But because even something as relatively simple as height is polygenic, there is no single candidate gene.

There is not even a group of genes.  In fact, if you really want to get down to it, you have to do what are called Genome Wide Association Studies, where you look at the entire genome at once and look for how variations from one person to the next might account for different traits, like performance (or disease, for example).

And when you do this, the numbers become staggering.  Most recently, a paper in Nature Genetics found that you could explain 45% of the variance in height by using 3,925 unrelated people, and a staggering 294,831 different SNPs.  A SNP (pronounced snip), just to explain, is a DNA sequence variation, where for example Andrew might have a gene with a certain sequence, whereas Matthew has the same gene, but with a single change, a single 'different letter', that alters the function or effect of that gene.

In other words, it's not even as simple as having a gene or not, it now becomes a question of which variant in the gene you have!  If this is getting complicated, don't panic - it's because it is complicated!  The bottom line is that there is no such thing as a single gene that makes one person tall and another short.  There are hundreds of thousands of different gene variants, and these variations change the phenotype (the effect of the gene) so that you and a friend may have the same gene but because your SNPs differ, you have different traits or characteristics.

Let's just go back to that height finding, which bears repeating:  Height is almost certainly simpler than something as complex as human athletic performance, yet it requires almost 300,000 different genetic variants, and that helps us explain only 45% of it.  How many more SNPs or genes or DNA sequence variations might it take to explain sprint or endurance performance?  And this is why when you read that the latest studies have failed to find a gene that explains why Jamaicans are so fast, you should interpret it with the right insight because:

• they are often looking for a 'candidate gene' (or small collection of genes), which is a huge oversimplification of performance as a polygenic trait, and;
• there are simply not enough elite athletes in the world to be able to do the study that finds significant associations between that many SNPs and performance.  If it takes 4,000 people to explain less than half of height, then how many more may be required to explain sprint performance, of which height is only a small contributor?

This is also why those genetic tests that supposedly tell eager parents whether little Tim is going to be a sprinter or a distance runner are so over-rated.  These tests screen for several genes, including perhaps the most "famous" performance gene ACTN3, which is supposedly linked to elite sprinting performance.

The problem is, the studies comparing Jamaican sprinters and east African distance runners find no differences for that particular gene.  I hope I've shown you why this may be the case.  In the words of Prof Stephen Roth, one of the world's leading experts on genes and performance "It looks like the gene does contribute something, but only a very small amount at the very, very elite levels".  "Several genes" will sadly explain very little, except in rare cases.  And performance is not one of them.

So there is no single genetic predictor of success (or even of height), but this does not mean that genetics don't count towards success.  We are limited by our capacity to measure how these many thousands of gene variants interact, as the next study of training responses shows.

Genes and training responses:  Responders and non-responders

The next level of our genetic journey is to ask how genes impact on our ability to adapt to training?  This is clearly vital for aspirant elite athletes - whether or not you still believe in 10,000 hours, it's quite clear that some people adapt faster to training than others, or are able to more rapidly acquire skills than others.

The study that is needed to answer this question is to take a large, random group of people and expose them to training, and then to measure how much they improve.  And this has been done.  There are four studies, summarized in the figure below, where big groups have been put through a supervised training programme, and their VO2max measured as an index of fitness.

So, on average, VO2max will improve by 15% as a result of training.  In some studies, it's been as high as 19%, in others, 9%.  This may be due to differences in the training programme, or the people involved.  However, what you should be asking, especially given our look at Ericsson's violin study and the chess paper, is "What are the individual differences that make up that 15%, and what is the genetic impact in these studies?"

And for this, a paper by Claude Bouchard earlier this year.  In this study, 470 untrained volunteers were put through five months of training, and their fitness levels measured before and after.  The figure below shows the result:

As you might expect, most people improve by average amounts - 38% of the volunteers improved by between 300 and 500 ml/min (shown by they yellow and green bars in the breakdown of responders section).  But either side of these "typical responses", you see the extremes - the "low responders" shown in reds and oranges, and the "high responders" shown in blues and purples.  4% of the volunteers improved by 800ml/min or more, whereas 7% improved by less than 100ml/min.

Overall, there was a range of changes in VO2max all the way from 100ml/min (basically no improvement) to over 1000ml/min.  That's a 10-fold difference.  You may recall that yesterday, we saw how chess expertise showed an 8-fold difference between the fastest and slowest to succeed at reaching Master level.  It seems that a similar range of responses occurs for physiology.

The end result is that the bottom 5% of the sample, those who responded the least, improved their VO2max by less than 4%.  On the other end, the high responders, the top 5%, improved by 40%.  That is an astonishing difference, and the simple, and obvious question is where are you most likely to find an endurance athlete in this sample?  The answer is on the far right - the individual who shows large adaptations to training, improves quickly and then reaches a higher ceiling.  I am sure that every one of you reading this knows one of each of these people, perhaps you are one of them!

Note that this study does not take into account that ceiling, and nor does it account for the starting point.  Both of these may be influenced separately, and ideally what you need is a person who starts high, shows this kind of high response, and they are most likely to be the endurance achievers.

In terms of the genes, where's the link?  Well, Bouchard performed a genome-wide association study and was able to identify 21 of those previously mentioned SNPs (genetic DNA variations) that accounted for 49% of the difference in the training response.  As we saw for height, 49% is pretty solid, especially with only 21 SNPs - it suggests that height is not so simple...!

One of those SNPs was in fact responsible for about 6% of the training response, and as far as a single SNP goes, that's a pretty powerful association.  The figure below shows the association between SNPs and training response:

It turned out that the non-responders were people who had fewer of these SNPs than the responders.  If a person carried 9 or fewer of the identified SNPs, they improved by an average of 9% (about half the average), whereas individuals who had 19 or more of the 21 SNPs improved by 26% (almost double the average).  The three-fold difference between the responders and non-responders could thus be attributed to the presence of these sequence variations.  Not the genes - I can't stress enough that the search for a single gene is futile because performance is just too complex.  But rather individual variants that make up the response of VO2 to training.

And again, this is just one component of performance - think of the hundreds of other physiological attributes that make up an elite athlete.  The reality is that our failure to find a performance gene may be more a reflection on our capacity to understand the complexity of physiology and genes than it is an indication that genes don't make a significant impact.

The key genetic question: Same training, different responses?

The most powerful question, then, in my opinion, based on the above study, is the following thought-experiment:

If you took 470 volunteers from Kenya, and gave them the same training as was given to the 470 in the Bouchard study above, would you find the same range of non-responders to responders? Would you find that 7% of Kenyans improve their VO2max by less than 100ml/min?  And would you find that 4% improve by 800ml/min or more?

I would hypothesize that the whole curve would be shifted way over to the right - there would of course be low and high responders.  But the lower responders in the Kenyan sample, would, I suspect, be fewer and perhaps would improve by 200ml/min, not 100ml/min.  As for high responders, instead of finding only a few who improve by 40%, you may find many more.  This would be the indication of a genetic advantage - not that every single person is superior, but that within a given population (470 people in this case), you are more likely to find the physiological characteristics of a champion athlete in one group than in another.

And as soon as you super-impose the opportunity, the competitive environment, the altitude, the diet, the psychology, the culture and belief, the lifestyle, then you have the recipe for a distance champion - Kenya succeeds not because they have these factors, but because they apply these factors to an exceptional genetic pool.

Jamaica has the same scenario for speed, I would hypothesize:  a concentrated group of individuals who possess the necessary physiological attributes to run fast, and to respond enormously to power and sprint training.  Then onto that, you add the history, the role-models like Usain Bolt, the school competition, the excellent coaching, the culture of the island, and the result is the perfect mix to produce athletes who may well go on to win half a dozen Olympic gold medals.

No alchemy in elite sport - start with the right materials

But it all starts with the genetic potential.  In high performance sport, there is no such thing as alchemy - you do not make gold out of other metals.  If you want to produce a champion, a gold medal, then you must start out with the right raw materials.  Everyone will improve as a result of training.  Some, the lucky few, will start out at a level that is higher than the rest, and will improve more rapidly through training.  That this is linked to genes is, in my reading of the evidence, unquestionable.

There are other arguments, of course.  Some are obvious - your body size is strongly influenced by genes, and it limits the sports available to you.  For example, if you're 1.70m tall and weigh 70kg, you won't be playing high level rugby or American Football.  And definitely not basketball.  If you are 2.00m tall and weight 110 kg, then basketball or rugby are options, whereas long distance running probably isn't.  But these are almost absurd illustrations of how genes, which clearly determine these aspects of our physical makeup, influence performance.  But if this is true of these traits, then would it not be the case for something like hemoglobin, muscle enzyme activity/content, plasticity of the nervous system and motor skills?

Rate of performance improvement - a key symptom of innate ability

Last example - I was asked yesterday in a presentation on this subject whether a parent should try to 'diagnose' their child's potential using the genetic tests.  I explained above that these tests have very limited potential to do this, to the point of being useless.  It did get me thinking though about what we look for to detect whether those genes are present.  How does one know that a person has innate ability over and above the typical ability to learn any activity?  And I believe the key, as illustrated by Bouchard's study, is the responsiveness to training.

Of course, the starting point is also crucial, especially for sports that are "physiologically limited" (like running, cycling, swimming, triathlon, where muscles, heart, lungs and brain provide a ceiling for ability).  But for skill-based sport, where training time does matter, the key is how quickly the skill or ability can be acquired - this is the symptom of the innate ability.  I was asked about the Polgar sisters, for example - these are three Hungarian sisters who were taught by their father to play chess to prove that "genius are made, not born".

The coaching of their father, along with professional chess players who were employed to teach the three girls the game,  produced outstanding chess players.  Two became grandmasters, one an international master. Judit Polgar is the most accomplished female chess player ever.  Their story is often cited as a nurture over nature example.

But there are problems with that theory.  First, the fact that they were all family doesn't allow you to exclude genes.  But more than this, when you read the story and start to see not only what they achieved, but when it was achieved, it's difficult to make the case for many hours of training being the secret of their success.

For example, Judit Polgar, at the age of five, defeated a family friend (an adult) without looking at the board.  She defeats her father (a decent level chess playing adult) at five, and beats a Master level player at seven, playing blindfolded!  Remember that yesterday we saw that on average, it takes 11,000 hours of practice to become a master, and you realize how exceptionally talented Judit was.  She then beats an international master player at 10, and a Grandmaster at 11.  These are accomplishments that precede "many hours" of training.

Her sister Susan wins a local chess competition for Under 11s at the age of 4.  Within the first year of their exposure to the activity, they demonstrate exceptional ability, long before the 10,000 hours, long before the deliberate practice can explain their obvious ability.  What makes these sisters exceptional is not simply that they accumulate hours of training, it is that their ability to learn the skills is astonishing - defeating a Master at 7, while blindfolded, given that at most, you've done maybe 3,000 hours of training, is just a staggering illustration of superior ability, developed through training, certainly, but not a performance that you'll find in most people.

Sure, in order to continue to the Grandmaster level, to become the best in the world, it required more training.  But the trajectory was clearly there early, it was a symptom of innate ability, and so this is an argument for genes just as much as it is deliberate practice.

The Polgar sisters, to sum up, are the sporting equivalents of Missy Franklin or Michael Phelps - precocious talents who achieve within the first few years what others take a lifetime to do, and will often fail.  That is as much an argument for innate ability as it is for deliberate practice.  The only experiment that proves nurture over nature is if you can take 100 children, unrelated, and train them all to reach the same level of performance.  The simple fact is that this doesn't happen, and the reason is, at least in part, innate ability.

Conclusion: Two valuable frameworks, both absolutely necessary

I don't think it's revolutionary to suggest that BOTH genes and opportunity are needed.  In the scientific community, you'd be laughed at for suggesting this.  Most people believe that it's a combination of both, and that's why the current models, the best models for performance, integrate all these factors.  One such model is shown to the right - it's a framework for talent ID and development from a 2008 Sports Medicine paper by Vaeyens (click to enlarge).  It clearly includes natural abilities, catalysts, environmental factors and even chance.  These are the basis for current sports science beliefs, and the theories put forward in the popular media, and by Anders Ericsson, unnecessarily and incorrectly oversimplify this.

I can appreciate the value of the deliberate practice framework proposed by Anders Ericsson, popularized by Gladwell, Syed, Coyle etc.  It reinforces that we must better manage our entire sports environment to ensure that more potentially successful athletes are exposed to good coaching, good diet, competition etc.  This has implications all the way up to government level, where policies around sport are determined.  For example, in South Africa, sport is less accessible than it should be, partly because of the removal of sport from our school curriculum.  We also have a dearth of coaches, and few facilities - these factors combine to greatly reduce the chance that we'll produce a Phelps, Franklin, or even a great distance runner, regardless of the talent we have.

But equally, the realization that certain individuals have innate abilities that will help them achieve elite levels is crucial.  It influences where money is spent, how young athletes are steered, how athletes are encouraged to transfer from one sport to another (think of the lifesavers and sprinters who were given a shot at the Olympics and skeleton because of the Australian Talent transfer).  This too has implications for policy, and even for parenthood, in terms of understanding whether a child should specialize early or be encouraged to be as diverse as possible with their sport choices.

All in all, it's a fascinating debate, and thank you for your inputs and contributions to the debate so far.  As always, my aim is to have the first word in a debate, not the last, so I welcome more inputs.  In this post, I've proposed my theory, based on the early gene studies that are associating exercise performance with genes.  I've tried to highlight the complexity, and to illustrate that all is not as it seems.

The rest is for future studies, but I'll leave it with my ultimate conclusion.  To become an Olympic champion, the very best of the best, you need to tick the boxes.  Genes is without a doubt one of those boxes.  But so too are opportunities.  And so is success genetics or training?  It's both.  In fact, it's 100% genetic, and 100% training.

Ross

Talent, training and performance: The secrets of success

Genes vs training:  The secrets of success

Apologies for the post-Tour de France "black hole" that was The Science of Sport! Following and analyzing three weeks of racing left the inevitable backlog of work, which also happened to pick up to warp-speed at the conclusion of the Tour!  However, recovery time now over, I am in the process of putting together the next series, which I'll start as soon as I can, on The Physiology of Pacing Strategies. That will be a video series, consisting of perhaps six or seven short videos, which will bring us neatly to the IAAF World Championships in Daegu.

Genes, innate ability and talent? Or practice makes perfect? Is it all in the training?

But for this week, a few posts on a topic that is both fascinating and, for me, very frustratingly hyped in the media (and, interestingly enough, within sports science as well), and that's the issue of genetics/talent vs training as a requirement for success. I recently co-authored a review on this for the journal Dialogues in Cardiovascular Medicine, and am busy working on a second review on the relative contribution of genes and practice to performance. Those articles will be published in 2012 (I'll let you know when).   I have also done a few presentations on this in the last few weeks, at the University and to the public, so it's a topic that I'm pretty immersed in at the moment.

And then last night, I received an email from a journalist with the Evening Standard of London, asking for some thoughts on a piece that they carried a few days ago.  It was an article called "Why we're the best", and it speaks about culture, practice, genes (or the lack thereof) and other factors that determine why, for example, Kenya produces great runners, China great table tennis players and Australia great swimmers.

You can read that piece here, but I just want to highlight some of the key phrases that warrant a mention, and then evaluate them critically.  I'll do this in two parts.  

1. The first (this post) will look at claims about the role of training and practice on performance
2. The second (later this week) will look at genes and how genetics may influence performance.

Why we win: Culture, practice but not really the genes?  Champions are born, not made?

The video below shows Matthew Syed, author of "Bounce" and he puts forwards some of the same concepts as the article.  It's worth a look, because Syed makes a number of claims that really need to be tested or questioned. Watch the video below, and take note of the following statements by Syed

"Any validity"
"Utterly transform the people we are"
"all about genetics"
"that's not what the science is saying"



Then the following are quotes from the Evening Standard article, which further reflect this thinking:

Success, he [Peter Keen, director of performance at UK Sport] said, was "massively culturally determined" as it dictates what you can "interact with and what is denied you" as a sportsperson. Tradition, success, climate factors, cultural factors - these are more important than some apparently fundamental drivers, such as genetics. 

"To be a high jumper it pays to be tall and this is true if you're Chinese or British," he continued. "But the simple truth of any successful athletic performance is a minimum of 10,000 hours of deliberate practice. That is typically eight to 10 years of your life, two to three hours a day, motivated by the belief that you can be something special."

Later in the article, it talks about the failure to discover the "speed" or "endurance" gene:

But despite Professor Morrison's assertion, attempts to identify a generic speed gene are unsatisfactory.

The search has focused on a gene known as ACTN3. This is because there are two types of muscle fibres, slow twitch and fast twitch. Slow twitch fibres are more efficient in using oxygen to generate energy but fast twitch fibres fire more rapidly and generate more force. These are the ones believed to aid speed and ACTN3 is the gene considered key to their development. 

But despite huge testing programmes of Olympic athletes, not a single record-breaker has been identified with two copies of the variant in the gene. Dr Yannis Pitsiladis, who conducted tests for the University of Glasgow, says this means the impact of genes on identifying sporting excellence has too often been overstated. He adds: "To date there is zero predictive capacity in sports genetics."

Huge complexity, but an oversimplified, and unbalanced explanation

Let me start out by saying that culture, training, diet, opportunity are all crucial to producing sporting champions or elite performances.  But the problem with the debate as it stands is the relative dismissal of physiological factors like genes, and also the extremely oversimplified view that "it's all about the training", or that science suggests genes don't matter.  My purpose with these posts is thus not to dismiss the role of training, culture or belief, but rather to balance out the argument with the facts.

And in so doing, to give an indication of just how complex it really is - the only certainty is that whoever says that success is due to one or two things is wrong.

Testing the statements: The 10,000 hour concept

So there are a couple of claims in the above quotes from the article, and they're worth looking at a little more closely.  We start with the 10,000 hour claim in today's post.  Tomorrow, I'll look at the genes and the claims made about the absence of genetics.  

It is stated in the article that "the simple truth of any successful athletic performance is a minimum of 10,000 hours of deliberate practice".

Deliberate practice means dedicated training in that activity.  In this model, there is no such thing as talent transfer, and there is no is no allowance for accumulating training by play (this is a theory that has been challenged recently, but the deliberate practice model, which was proposed and really developed by Anders Ericsson, holds that only specific, dedicated training works.)

The origins of 10,000 hours

This 10,000 hour theory has its origins in a 1993 study by Ericsson, where he looked at the performance ability of violinists, and showed that the playing ability was determined by the cumulative hours of training up to the age of 20.  That is, the best experts had accumulated the magic number of 10,000 hours whereas those classified as merely "good" or "least accomplished" were found to have done only 8,000 or 5,000 hours of practice, respectively.  The graph below illustrates this main finding, where yellow and orange are the best performing violinists.  Clearly, the average time taken to get to the 'elite' level is 10,000 hours, at least when it comes to playing a musical instrument:

Exceptions to the norm:  What variance would indicate

There's another way to interpret this finding, which I'll get to later in the piece.  First, a major statistical "omission" in the paper undermines how the conclusion of Ericsson and those who argue for 10,000 hours can be made.

I have that study, and what is remarkable about it is that Ericsson presents no indication of variance - there are no standard deviations, no maximums, minimums, or ranges.  And so all we really know is that AVERAGE practice time influences performance, not whether the individual differences present might undermine that argument.  Statistically, this is a crucial omission and it may undermine the 10,000 hour conclusion entirely.

I must emphasize this point strongly: If the theory is that 10,000 hours of practice are needed, and there is no innate ability, then you should not find a single person who has succeeded with fewer than 10,000 hours, and nor should anyone fail having done their 10,000 hours.  Take a look at the graph below.  I've highlighted only the "best expert" and "least accomplished" players, and shown some hypothetical dashed lines to show the ranges within each group.  

It's conceivable that there is a range of practice times within each group, such that there is a person in the "least accomplished" group who does 10,000 hours (shown by the blue circle) without cracking that performance level, and a person who does less but succeeds (shown by yellow).

Unfortunately, Ericsson didn't show us this data, so we can only speculate.  But that didn't stop Malcolm Gladwell from making this statement in his book "Outliers":

“The striking thing about Ericsson’s study is that he and his colleagues couldn’t find any “naturals”, musicians who floated effortlessly to the top while practicing a fraction of the time their peers did.

Nor could they find any “grinds”, people who worked harder than everyone else, yet just didn’t have what it takes to break the top ranks.” – Outliers, pg 39

Again, I don't know how he arrives at the above statements - Ericsson presented not a single measure to support these claims (and I happen to know that he didn't interview him either).  As we'll see shortly, it is actually inconceivable that Gladwell's statements are true - other study of skilled performance show massive variations, and the same will be true for violinists, of this I'm certain.

But what he is saying above is that practice is NECESSARY (the first part of the quote - no one succeeds without doing the time), and that practice is SUFFICIENT (the second part - if you do the training, you will achieve the level).  This is crucial to this debate - those advocating for 10,000 hours are saying that it is both necessary and sufficient.

Gladwell reinforces this when he goes on to quote someone called Daniel Levitin:

“The emerging picture from such studies is that ten thousand hours of practice is required to achieve the level of mastery associated with being a world-class expert – in anything…no-one has yet found a case in which true world-class expertise was accomplished in less time” – Daniel Levitin, quoted in Outliers (emphasis added)

That all of the above are claims are enormous oversimplifications and without evidence becomes clear when you consider "what the science is actually saying", to borrow Syed's words from the clip above.

10,000 hours: Unnecessary and/or insufficient

So we start looking for evidence to test Levitin's (and others') statements about 10,000 hours being both necessary and sufficient.  We do this by disproving it, and begin with chess.  Gobet and Campitelli studied 104 chess players and measured practice time and performance level, and looked at the time taken to reach the Master level.  This is their finding:

So, the average time taken is 11,053 hours.  That's pretty much in agreement with Ericsson's violin players.  So far so good.  But look at that Standard Deviation - 5,538 hours, and it gives a co-efficient of variation of 50%.  For those not into the statistics, what this basically shows is a "spread" of the values around the average.  If the Standard Deviation is small, and the CV is low, then you have a tight cluster - all the individuals are close to the average.  But when it's 50%, then you know you have massive differences within that group.

And that's what happens when you start looking at individuals - one player reaches master level on 3,000 hours, another takes almost 24,000 hours, and some are still practicing but not succeeding.  That's a 21,000 hour difference, which is two entire practice lifetimes according to the model of practice.  It seems pretty clear that practice, while important, is not sufficient for some.  And for others, it's not even necessary.

But let's look at other sports.  Darts has been studied, by Duffy and Ericsson.  They find the following when looking at darts scores and accumulated practice time:

The figure above shows how much of performance can be explained by deliberate practice. In chess, which I showed above, it's 34%.  In darts, 15 years of practice explains only 28% of the variation in performance between individuals!  An extra-ordinary finding, because with all due respect, that's in darts...what else is there that influences performance?  Yet practice time accounts for only a quarter of the performance differences.

What is most interesting about this is that 10 years of practice explained 25% of variability, while 15 years explains 28%.  So clearly, the more you practice, the more you can explain performance.  That's not surprising, but the question is this:  How many hours of practice would it take to explain "most" of performance as a result of practice?  Look at the quote in the figure above, where Ericsson writes that "the development of expert performance will be primarily constrained by individuals' engagement in deliberate practice" (Ericsson, 2009).  Well, 28% is not "primarily constrained" and even though more practice explains more of performance, there is clearly a lot missing from this practice argument.

Sports examples: Very rarely do elite athletes need 10,000 hours

So far, we've looked at chess and darts, both skill sports, but neither is "physiologically-limiting" in the way that running, cycling or swimming may be.  So let's expand our examples and look at other sports.

Start with Olympic wrestling, football and field hockey.  Below are the findings from research on the USA Olympic athletes.

Clearly, 10,000 hours are rarely required. A subsequent study on Australian athletes found that 28% had participated for fewer than four years in their sport - that's probably 3,000 to 4,000 hours, at most.  One netball player from Australia had made the international stage on 600 hours of play.

Accelerated Talent ID and talent transfer

Australian skeleton is another interesting example - in 2002, they decided to adopt a systematic, accelerated talent ID approach to skeleton, and looked at sprinters, lifesavers and speed-skaters to find an Olympic skeleton athlete (Bullock et al, 2009).  It took fourteen months and they had qualified athletes for the Olympic Games, despite no ice-experience, and despite the prevailing wisdom that you "have to learn a feel for the ice" through years of practice to become elite.

Similarly, in the UK, they have had amazing success with accelerated talent ID and talent transfer, producing world champions within years of first introduction to a sport.

And I must emphasize this point - if the 10,000 hour concept is true, and it really does require that this time be accumulated (that is, if 10,000 hours is necessary), then talent transfer would be impossible, as would accelerated performance trajectories that we've seen in Australia and the UK.  And if genetics played only a small part, as some have argued, then Talent ID would also be wasteful and unnecessary, because any aspirant athlete would succeed, regardless of genetic "potential", providing they did the required training time.  This is clearly not true - the actions of federations who invest in Talent ID suggest that despite their talk, they don't believe this anyway.  But more on this tomorrow...

One important point is that different sports will have different requirements, different capacities for talent transfer and accelerated performance, and thus training time.  Rowing, cycling, and canoeing are perhaps easier to learn later in life than skill-heavy sports.  I dare say that tennis, golf may require much earlier exposure and training time - the skill component forces this.  Similarly, sports like football or rugby may also require early exposure, because the tactical insights and understanding are crucial to success.

However, even here, it's possible to identify who will go on to become a professional within the very first years of playing the sport - the Gronigen talent studies have shown this, where at the age of 14, children can already be picked as future professionals because they develop skills, improve endurance and learn tactics faster than their peers.  Differences in how quickly athletes improve, even in skill sports, suggests innate attributes that are predictive for success.


Greatness is recognizable early, long before 10,000 hours are accumulated: Michael Phelps and Missy Franklin


Having mentioned the fact that skill sport success can often be predicted very early, long before a player has accumulated 10,000 hours, it's worth looking at the examples of two swimmers at this point in the debate.  Michael Phelps is the owner of more Olympic golds than any person in history, and his story reveals that greatness can be recognized very early on.  He has told this story and described how he started serious training at the age of 11, doing approximately 1,000 hours per year.

At the age of 15, he was finishing fifth at the 2000 Olympic Games in Sydney.  At 19 he wins 6 golds, and then 8 golds four years after that in Beijing 2008.  But the key is that first Olympic performance, fifth at the age of 15, after only 4 years of training.  Some will argue that the difference between Phelps in 2000 and Phelps 2008 is eight years of training.  I'd say you are partly right, but to me, the bigger issue is physical development - a fifteen year old boy finishing fifth in the wold, no matter how physically developed, is clearly marked for great things very early on in their career, long before 10,000 hours are accumulated.

Missy Franklin is equally telling.  At 16, she won 3 gold medals (and five medals in total) in swimming in Shanghai recently.  And she failed to even qualify for the US Olympic Trials at 13, only three years before.  So her rise has been, to put it mildly, meteoric, and her arrival as a the best of the elites, precedes 10,000 hours by a long way.

My question to advocates of a "genes are less important model, it's about training" is how does this athlete become a world champion at 16 and with relatively little training, whereas thousands and thousands of others, who train maybe more than she does and over a longer period, will never even make the USA team for swimming?  In fact, the question should always be turned around - don't ask why some succeed, rather ask why most fail?  For every example of a champion, there are thousands who get the same training, the same opportunity, but fail to even make national level, let alone become a world champion.  Why?  The answer to this question, and the question of why the likes of Missy Franklin succeed, is genetics and INNATE TALENT.  As mentioned, more on this next time.

Innate ability as a catalyst for training: The alternative theory

Finally, let's go back to the violin study and let me suggest a possible alternative theory for why the best expert performers tend to train more.  

Ericsson concludes that these children just accumulate more training time and that this explains performance.  The difference between the "best experts" and the "least accomplished players" is the training time.

But what if it is exactly the other way around?  Let's take two children at nine years old.  Do they have the same ability to play on first exposure?  Ericsson's model says yes, and that the difference comes later, when one child practices more, gets better teaching.  But what if the difference is present from the very first note, the first exposure to the activity?  The parents of a child who shows some ability encourage further practice, they invest in teaching and training, and this child, by virtue of the fact that he/she has more ability to begin with, accumulates more practice.  

But the child who has little innate ability makes the violin sound like the death march of stray cats, and their parents do not encourage more play.  In fact, they discourage it - the "go play outside" syndrome takes over, and the child is never exposed to teaching or practice.  His trajectory is set precisely because he has less innate ability.

My point is that the above graph can be explained just as easily using an innate ability argument as it can a deliberate practice argument.  The current explanation is been practice, but given what we know about genes, I'd argue that the 're-inforced' behaviour catalyst/filter explanation is just as likely.  Those who display greater ability early on (innate ability, that is) are encouraged to practice more, and they set out on that journey towards "best expert" levels, the yellow line, from the beginning.  Those who lack innate ability are placed on the blue line.  No amount of training will change this, but the behaviour is set early so we never find this out.  The result is that ability is determined by practice, on average, but that practice volumes are perhaps themselves influenced by innate ability.  

Until someone shows that individual differences in performance can be made to disappear with training, and that the differences we measure in performance are not present from the outset, I remain skeptical about an extremist view of performance being due to one factor.

The importance of practice: Practice is vital, but extremist arguments just don't work

Now, I don't mean to be dismissive of the importance of training.  Of course, practice is vital.  It is a pre-requisite for success, especially when you have a competitive sport where many are vying for the same medal.  In that situation, the person who succeeds must train hard.  But their ability to get more out of training, to adapt to training and also to start off from a higher "baseline" is just as important, and those are factors influenced by genes, as I'll cover in the next post on this topic.

To argue that it's about the training, and to dismiss that genetics play a significant role, is to adopt an untenable and grossly oversimplified position.  The 10,000 hour concept is a nice motivational tool, a way to encourage more training, to inspire people to improve.  The idea for elite performance is that the right person hears this and believes, and then does the training.  But to attribute success to 10,000 hours of training is not only over-simplified, it's wrong.  Matthew Syed, in the clip above, says that one will argue that you "need both talent and opportunity, but that's not what the science is saying".

The truth is, the science is saying exactly that.  Make no mistake - producing champions is incredibly complex.  The success of Kenya at distance running, or of Jamaica in sprinting, cannot be reduced to one, or even a few factors.  You will find altitude in many places.  You will find socio-economic similarities all over the world.  But you won't find champions.

Success is probably due to hundreds of different factors, all interacting with one another.  But the end result is that if you take 100 aspirant athletes in Kenya, and 100 aspirant athletes in the USA, and expose them to the same training, you will not see anything like the same success rate.  And that is due to genetic differences that are too complex to discover with the approach that has been adopted so far.

In this post, I've looked at the training and practice factor, and hopefully given a broader view on it than the terribly simplified version that 10,000 hours is what it takes.  Next time, the genes, and the very certain finding that genetics is vital, both in determining innate ability, and our response to training, and even our motivation or desire to exercise and train in the first place.

Ross

Home-ground advantage in sport: Theories

Home-ground advantage - theories and stats, Part 1

***Click here to see Ross of The Science of Sport talk you through home ground advantage in three video presentations, covering the theory and the stats.***


This past week in South African sport was punctuated by, among other things, a discussion around travel and the effect it has on professional sports teams.  The specific subject was the Sharks, a professional rugby team from South Africa, who flew to New Zealand for a playoff match in the Super 15 Rugby competition.  That discussion has turned out to be a nice catalyst for a couple of posts on home-ground advantage and the factors driving it (Part 1), followed by a post by Tuesday on travel and some interesting stats on how Super Rugby is influenced by both factors (Part 2).

Super 15 - an extreme model to study home-ground advantage

The Super 15, for those not in the rugby loop, is a tournament played between professional teams from South Africa, New Zealand and Australia.  It is now two weeks from its conclusion and is into the playoff phase.  The vast distances that are required, as well as the altitude for some teams in South Africa, make it a really great model to study home-ground advantage.  In fact, I'd go so far as to say it's unique in this regard, in that it has extreme travel (10 time zones a trip) and large changes in altitude (0m to 1600m) on a weekly basis.  But more on that next time...

Of course, travel is only part of the home-ground debate, but for the Sharks, it was the big one - they decided to leave South Africa on Tuesday, four days before the match, and so arrived, 10 time zones to the east, with only 2 days before a huge match.  The question then was whether it would be possible for the players to recover and perform optimally?

I thought it was pretty certain that they would not, which I said in the article.  Turns out they lost, 36 - 8, which is a pretty heavy defeat at this stage in the competition when you consider it's between the best of the remaining teams in the playoffs (3rd vs 6th in this case).

Of course, it would be an enormous oversimplification to say that the loss was due to travel fatigue, because sport is way too complex to reduce to one variable.  However, I think it probably played a part, particularly at the end of a long season and after some very physically demanding matches in the weeks before.

What wasn't quoted in the article was that I was of the opinion that the match would be very competitive for the first 30 to 40 minutes and then the scoreline would blow out.  The Sharks probably needed to be 10 points ahead with 20 minutes to play, because fatigue would influence performance more later, whereas motivation would "hide" it for a while, before it eventually told.  That fits with what eventually happened - it was competitive half-way, and the big defeat was inflicted in the second half.

Zero from 32 - the challenge of travel in Super Rugby at the end of the tournament

How big is home-ground advantage in the Super Rugby competition?  Well, consider that since 2000, not a single team has won a playoff match outside its own country.  That's 11 years, and thirty-two matches (they have playoffs and semi-finals), and not once has an international away team won.  Admittedly, part of this is because the home team is at home precisely because in the course of the season it has been better than the visiting team, but still, zero from 32 in a competitive tournament is a telling stat for how difficult it is to travel overseas in the final few weeks of a four-month long tournament.  

The main reason for that, I'm convinced, is travel, but I'll talk about travel in the context of Super rugby in Part 2 later this week.  First, let's look briefly at the science of home-ground advantage.

Home-ground advantage - consistently 50 to 70%

There is no question that home-ground advantage exists.  This article presents some numbers from US-sports, saying that in basketball, the home team wins 62% of matches.  In baseball and ice-hockey, 53%, and in the NFL, anything between 54 and 64%.  There is some evidence in football (that is, soccer, to avoid confusion!) that playing at home is worth 0.4 goals (1.5 vs 1.1 goal to home and away team over 5,000 analyzed matches).

For rugby, it's never been published, but I have done an analysis of the last five years of Super Rugby competitions (the format and number of teams changes every few years, so it's a shorter period) and in Super Rugby, the home team has won 61% of the matches they play.  If you break this down further into away matches against "national" teams compared to away matches internationally (ie: NZ side playing an SA/AUS side), then the figure is close to 80%, which is enormous.


You see the same thing, equally strikingly, when countries host international sports events like the FIFA Football World Cup or Olympic Games.  Medal hauls almost always increase at home.  There is a little more to this than simply competing at home, because the host nation almost always injects massive capital (human and financial) to improve sports performance, which is possible because countries know many years in advance that they are going to host.  So Olympic hosts perform better, but it may be due to increased spending to prepare athletes, in addition to the factors I'll discuss below.

Factors influencing home-ground advantage

This is a somewhat simplified summary of what we know, but generally, there are four factors influencing home ground advantage:

1. Travel fatigue for visiting teams
2. Familiarity with the city, the facilities, the playing arena
3. Crowd factors, which can be further broken down into:
1. How the crowd influence the players
2. How the crowd influence the referee/officials

As mentioned, I'll tackle travel tomorrow, when I talk about Super Rugby, so let's look at the others, in reverse order.

The crowd influence on officials - a subconscious bias

Starting with the referees (a favorite of sports fans everywhere!), there is a real perception, true or not, that visiting teams are often ‘robbed’ by referee decisions. It turns out this is not a perception without some merit.  Studies have found, for example, that visiting teams in ice-hockey and basketball concede more penalties and have more players sent off for foul play than the home team.

It's also been found that the discrepancy in penalties awarded to visiting and home teams increases as the crowd increases in size.  And that when two London teams play football against each other, thus reducing the "unevenness" of crowd support, the discrepancy is reduced, suggesting that this may be the influence of the crowd on the referee. Even the most neutral and professional referee, with no intention of cheating can be swayed by the cheers or boos of a crowd.

For example, one study had football referees make judgments based on video footage of obvious foul play, but some refs watched without sound, while others watched with full sound, including crowd reactions to fouls. It turns out that with the sound, the referee is more likely to be swayed towards what the crowd is calling for - fewer free-kicks to away teams, more to home teams, no foul when the home team is guilty.  This is summarized in the figure below. And this is just on a TV screen, away from the cauldron of pressure of real-time action, where the crowd may have even more influence.

Further supporting this idea is that in the Olympic Games, the host country often wins significantly more medals, but most of them come in the subjectively scored events (ice-skating, gymnastics etc).  Given the football referee study, it's not difficult to see how a rapturous cheering crowd might be worth half a point here and there to a judge, despite their best efforts to block out crowd factors!

I must point out that there is other possible reasons why visiting teams are penalized more. One is that the "hostile environment" of the away arena produces a “victim” or “us against the world” attitude that sees visiting teams play more aggressively than they would otherwise.  This has in fact been documented for visiting teams, and, on occasion, for home teams, depending on the context of the match and the crowd behavior.

Also, the home team is often more aggressive and dominates play (defending their territory, perhaps), forcing the opposition to concede penalties as a result of applied pressure.  One analysis of decisions in the NHL found no difference in mistakes between home and away teams, suggesting that the penalty discrepancy may be justified (I am not quite sure how to reconcile that with the football study above, where the refs were making different judgments of fouls simply because of sound...)

Crowd influence on players - motivation, desire and anxiety

Harder to measure, but possibly as significant, is the effect of crowd support on player motivation and effort.  Certainly, sport is filled with testimonies of players who find "something extra", who raise their level because they're at home.  I guess one needs to be careful about taking a collection of testimonies and saying they are evidence (the plural of anecdote is not evidence!), especially because linking these factors to performance is very difficult.

But there's no question that "psychology" (an incredibly broad term) plays a role in sports performance.  But the sword may cut both ways when it comes to home-ground advantage.  A visiting team, with the odds against them, may well perform better than at home because of the desire to silence the crowd, and because of the added prestige of beating a team in their own country - I've experienced this with the SA Sevens side.

On the other hand, the effect of the crowd and the momentum they may give to players (who, for all the talk of "zoning the crowd out" must surely be aware of it) may be decisive - I have also experienced this with the Sevens team.  If you were to define a set of psychological requirements for success, you'd almost certainly put "confidence", "self-belief" and "high level of motivation" on the list, and in theory, that's what being at home brings.

To throw a curveball at that oversimplification of the theory, there was a fascinating opportunistic study a few years ago when a college basketball team had to play 11 of their matches behind closed doors because of a measles outbreak that forced the school to be quarantined.  It turned out that the team played better WITHOUT fans!  Their stats were up - more points, more free-throws and better shooting percentages.  Of course, 11 matches is a small sample when you consider how many factors might influence each performance outcome, but it does suggest that perhaps, fans influence players negatively, through increased anxiety.  Maybe the other team is just more anxious, and plays relatively worse!

Familiarity - 'no place like home'


The fourth and final factor, which is linked to the psychological factors I mentioned above, is familiarity with the playing venue, the weather, the training facilities, and also the people who the player encounters in the week leading up to matches.  There's some evidence for this too.

For example, in 37 sports teams who moved to a new stadium, home ground advantage fell by 25% in the first season at a new home (this is a small sample set, it must be noted, given the complexity of sports performance). The advantage still exists, but they are thus less likely to win at home than before.  Over time, this advantage returns.

Two things are in play here. First, they are no longer as familiar with their own stadium, and as trivial as it may sound, I believe this is a crucial aspect to performance, because it influences routine, focus, relaxation, confidence, and expectation prior to matches.  There may even be a more "primal" factor, in that the home team is protecting its territory, a theory that coaches play up all the time - the "our house" speech you may have heard a variant of!  New stadium, less territorial, less advantage?  Perhaps.

The second factor is that the visiting teams no longer have a potential psychological hurdle of entering the “fortress” that may have existed before.  This introduces the other side of the debate - the mindset of the visiting team.  In South Africa, we have a couple of rugby venues that are hostile to visiting teams, and knowing a few players, they don't particularly enjoy going there!  The media tend to hype up the fortress idea, and while players should in theory be able to resist this kind of intimidation, there's no question that mindset may be changed by the awareness of an away team.

In my experience, I actually feel that sometimes it is played up too much within teams.  Coaches and players always tell the media that it's still a game between two teams, a ball and four white lines, but they often create confusing internal messages, trying to downplay the mental aspect while simultaneously trying to inspire players to "be ready for the onslaught from the home team".  If any of this impacts the player, then home-ground advantage may have an effect through negative influences on the visitors.

Then there are also very specific factors - the Lehrer article talks about Boston's old basketball court with its uneven parquet floor and dead-spots, which visiting teams did not know about.  Weather conditions can influence this significantly (wind and rain adapted teams will thrive in their own conditions), as can pitch conditions (cricket is a big one for this).

In my experience, familiarity is a really crucial factor, perhaps the main one (though this is just my opinion born of my experiences with the Sevens side).  I believe it reduces anxiety significantly, and even allows players to find visual cues in the stadium that may help their performance.  Much of this happens away from the venue - it's in the hotels, the people, the food, the TV stations in hotels, the sights and sounds.  Just having family and friends around in the build-up is significant, provided it doesn't cause over-arousal.  The key is whether the familiar experience is a positive one or not.  Positive experiences are easy to reinforce, and so a player will be more optimistic, more confident when playing at home.

Experience counts - reducing home ground advantage?

This is why experience is such a vital factor for success in tournaments away from home.  Later this year, the Rugby World Cup takes place in New Zealand, which has historically been an incredible place to win.  There are a number of reasons for this - New Zealand has historically been the world's best team, so really, they'd be difficult to beat anywhere.  But the weather and travel distances don't help, and nor does the psychological block that teams take with them when they go there.  Positive experiences erode these factors, and so teams who want to succeed, will, I believe, have to rely heavily on players who have been there, won there, and know the stadiums, hotels and people.

Whether or not any of the above factors translate to better performance, I don't know, but I guess the bottom line is that playing at home CAN bring what sports psychologists recognize as crucial to optimal mental performance.

But then again, it's still four white lines, a ball and the same set of rules!

Travel

The factor I've left out is travel, and that's because it's worth a post of its own, especially given the Super 15 motives behind this post.

That comes tomorrow, so join us then.  Also, don't forget to get on Facebook and Twitter if you're on them - I try to use them as a supplement to the site, posting some thoughts, opinions and links to articles of interest.

Ross