Welcome to the Science of Sport, where we bring you the second, third, and fourth level of analysis you will not find anywhere else.

Be it doping in sport, hot topics like Caster Semenya or Oscar Pistorius, or the dehydration myth, we try to translate the science behind sports and sports performance.

Consider a donation if you like what you see here!


Did you know?
We published The Runner's Body in May 2009. With an average 4.4/5 stars on Amazon.com, it has been receiving positive reviews from runners and non-runners alike.

Available for the Kindle and also in the traditional paper back. It will make a great gift for the runners you know, and helps support our work here on The Science of Sport.



Wednesday, June 23, 2010

FIFA 2010 World Cup: Goals and tactics

Goal scoring - on the up:  Thoughts on tactics, and the infamous Jabulani ball

We're now into the final round of matches in the group stages of the 2010 World Cup, and the number of goals being scored has certainly increased.  Goals were a rarity in the first round - only 25 in the first 16 matches, by far the lowest in any round of a World Cup, at least since 1998 (there were 58 cards in the first 16 matches - more than twice as many as goals.  The normal ratio is ± 1:1.3)

In the second round, 42 goals were scored in 16 matches, a healthy increase, and hopefully one which will continue into the final batch of matches, now underway.

Why so few goals: Typical play, or false explanation?

One interesting observation I will make regarding the goal scoring is that a lot of commentators have remarked that low scoring is "typical in the first round" as a result of the pressure and the desire to avoid defeat in the first match.  A statistic that backs this up is that 87% of teams who lose their first match in the World Cup will fail to qualify, compared to 50% who draw and 86% who win.

So clearly, the pressure is on to avoid defeat.  And it is this pressure, which drives a conservative and defensive approach, which has been described by studio analysts and commentators, as the reason for the relative scarcity of goals in the first round.  The extension is that now that the tournament has opened up, and teams are in 'must-win' situations, they will play more adventurous football.  This is argued to be normal in a tournament like this, something to be expected - "the goals will come later, this is normal", they often argue.

And the tactical explanation may well be true.  It certainly sounds reasonable.  But it's certainly not backed up by the data, and so when it has been described as "normal" and "typical", it is an error which a simple count would confirm.

Below is a graph showing the number of goals scored per round in each of the last three World Cups and the 2010 tournament.

It's quite clear that there is no relationship between goals scored in Round 1 and Round 2 - in 1998, goal scoring increased from Round 1 to Round 3. In 2002, it dropped dramatically and then rebounded, as it did in 2006.  In 2010, we've seen a huge jump.  The only consistent finding in the last 3 tournaments (and I stress that this is a small group) is that Round 3 produces the most goals.  This is relatively easy to justify - teams have much to play for, nothing to lose etc. and so they are much more open.  This may be true, again, but it may also be that teams have figured one another out and know how to approach matches (remember that these teams play each other maybe once or twice every five or six years).  I'll be surprised if the same happens in 2010, but time will tell.

The point is, there's no "typical pattern" from Round 1 to Round 2.  The number of goals might well be influenced by a collective desire of teams to avoid defeat, but this can't be described as typical or normal.  It's easy to make these assumptions, because they sound so reasonable.  The point I'm emphasizing is that sometimes even experts will rationalize their observations, explaining away a finding like 25 goals in 16 matches with what are perfectly reasonable theories, but which don't always account for the historical observations.

Again, this does not make them incorrect, but one would have to then explain why teams have been ultra-defensive in 2010, but were not in 2002 or 2006.  Or perhaps they were, but the match-ups offered simply allowed more goals to be scored.  For example, Portugal hammered North Korea 7-0, somewhat inflating the 2010 Round 2 tally.  Had that game been played in Round 1, perhaps 25 goals would have been 32?  Rational explanations, however reasonable, often only tell part of the story.  And sometimes, we seek patterns where there may be none!

Other potential factors:  Altitude and the ball

I know I'm dwelling on the altitude issue somewhat, but I do believe it has had a significant effect on the World Cup so far.  I am in the process of gathering data on the effects of altitude on performance, and I will publish that here (in something of an "exclusive") once the tournament has been completed. 

But the other effect of altitude is on skill levels, specifically ball-control.  So far, we've seen some unexpected errors by players - goalkeepers are always exposed more than outfielders, but all around the field, there have been some glaring mistakes.  Until South Korea scored their second against Nigeria yesterday, not a single direct free-kick had found the goal, and I can think of only a handful where the goal-keeper has even had to make a save.  In general, long-range shooting has been abysmal, and for this, the Jabulani ball and the altitude have taken much of the blame.

I would suggest a combination of the two factors.  Fabio Capello has labelled the ball "the worst ever", and Dunga and many players have been equally critical.  I don't think it is the sole factor, and I don't even believe it is all that bad - perhaps different in its flight, but the accusations of it being "supernatural" are either over-reactions, or a deliberate marketing ploy by Nike to have their sponsored teams and players undermine Adidas' World Cup sponsorship (there is a billion dollar battle going on off the field!  I'm being cynical, but with reason!)

The other factor is altitude.  Balls fly faster, further and have less dip and bend than at sea-level and I believe that players have struggled with this.  In the matches I have watched live, the speed of the ball off the surface has caught a number of players out, and crosses have been over-hit regularly.  This is a combination of altitude, the ball, and possibly the playing surface, though little has been said about this.

For a few interesting thoughts on altitude and the ball, this site is well worth a visit - it is devoted to understanding the physics of sport, and their latest articles deal with the two big issues of the moment:  The ball (Is it possible to engineer a perfect ball?), and the altitude (does altitude affect tactics?)

But perhaps the players are now gradually adapting to the conditions, to the ball, and also beginning to work out the opposition, and this is much responsible for the now normal goal-scoring in the second round of matches as the tactical approach is?  On the tactical analysis, as technology evolves, and the ability of coaches and players to "research" their opposition improves, defense will always improve faster than attack, because it is easier to control the game without the ball than with it (the same is true of rugby, where not having the ball is an advantage).  And so the growth of knowledge of the game, made possible by computer software and mobile technology, will inevitably see tighter competition.

Or maybe all these theories are just trying to explain something that doesn't exist - time will tell, but hopefully, the goals will keep coming!

Ross

4 Comments:

Morten said...

I clearly see a pattern. The third round has ALWAYS produced the most goals. Obviously this might be down to chance. And indeed if the scoring was random, there would be a 1 in 9 chance of observing the most goals in the same round three times in a row.

Also, you cite the statistic on chances of progress if losing/drawing/winning the first round. How do those compare to losing/drawing/winning in the second or third round. The statistic is, in my mind, a bit useless without this comparison.

Ross Tucker and Jonathan Dugas said...

Sure, there may be an increase in the third round. Given that the 3rd round of the current tournament hasn't finished yet, I'm going to wait before pronouncing this as "clearly" evident. There are some very obvious factors that may account for this - one is the number of 'dead' matches by this stage of the tournament, where teams have nothing to lose, or nothing to gain and play much more openly.

I'll have a look at this towards the end of the tournament, once the group phase in 2010 is over. Until then, this post was mostly meant to look at Round 1 vs Round 2, so Round 3, for now, is a theory...

As for the stat, 80% of teams who win even one match will advance to Round 2. So it doesn't matter much where you win, as long as you win - this is obvious in a 3-match group format with 2 to advance.

JZ said...

I think the majority of the teams (especially those sponsored by some other ball manufacturer) failed to take the time to truly get used to how the Jubulani played. In the second and third rounds the teams seem to be getting the hang of the ball and combined with more aggressive play are scoring more goals.

Of course that begs the question of whether a ball should be so different that it requires some getting used to. I would suggest not. They should have just changed the graphics on the ball that was used for the UEFA cup.

Morten said...

Fair points. Have you checked if the dead rubbers indeed produce more goals?

And for the losing/drawing/winning statistic, this is exactly my point. It can not account for the (alleged) tight first game. Winning/drawing/losing matters equally over the three games, so no point in having a special tactic in the first game.

Also, do you have some comparisons back to the 1994 and earlier world cups wich had only 6 groups and hence 4 of the 3rd place teams also progressing. What would be the prediction for 'tightness' in the first round?