The Biological passport stands up to test 3

Valjavec ruling:  CAS further strengthens the biological passport

One last short post, just to give a bit of significant news in the world of cycling.

It is significant in that it boosts the efforts of the biological passport even further, and it is significant because it follows on from a series of posts we did just over a month ago on the biological passort, its scientific and legal issues.

That news is that Tadej Valjavec has been banned for two years on the basis of the athlete biological passport system.  The ban is an overturning of an earlier Slovenian decision to clear the rider.

Some articles summarizing the Valjavec ruling can be found here and here, and they explain how the passport has received yet another boost as a result of this decision.  This follows on from the CAS decisions to uphold the ban of Pietro Caucchioli and to overturn a CONI decision to exonerate Franco Pellizotti in early March.  The second decision in particular was significant, because CAS ruled against the Italian federation that had cleared Pellizotti despite biological passport figures that were deemed suspicious.

The same has now happened for Valjevic - he was initially cleared by the Olympic Committee of Slovenia, on the basis that he argued that his suspicious values (strikes, as we called them in our series) were the result of an ulcer.  His case was apparently very well presented, with some serious "heavy-weight" experts arguing it out before the CAS.  This was therefore the most stringent legal test of the passport to date - we discussed in our articles the legal issues, and the chances of "false strikes" against riders.  Valjevic tested that system to its limit, and it came out stronger, and that's a great step forward for the passport system.

CAS said in a statement that "The CAS has set aside the decision of the OCS to exonerate the athlete from any doping offense and has imposed a two-year ban on him starting on 20 January 2011, as well as the disqualification of all his results obtained between 19 April and 30 September 2009 and a fine of EUR 52’500".

Every one of these cases strengthens the legal basis and adds momentum and "clout" to the biological passport system.  CAS used the precedent set in the Caucchioli and Pellizotti cases to make this ruling, and further cases like this are likely. 

Our articles on bio passport, which include some great discussion, including inputs from those scientists who are actually responsible for the passport's creation and implementation (for which we are enormously honoured) can be found here:

1. The legal, scientific and performance viewpoint of the biological passport
2. Evidence that the biological passport IS proving effective in the fight against doping

All in all, the passport may not be perfect, and yes, athletes will micro-dose and get away with doping, but as we showed (in Part 2 of the series), it's making a difference.  And now the CAS are supporting that effort and adding weight to it.

That's all, see you after Easter

Ross

Boston "not significantly aided"? The ARRS stastician view and its faults

Boston was "not excessively aided" say the ARRS. But their conclusion has (major) problems...

We hope everyone is enjoying a timely Easter break.  Having wrapped up Boston in my previous post, I received a few emails and comments about another analysis of Boston, and thought I'd comment briefly on it here rather than in the discussion thread to previous posts or on Twitter!

So the following article was released today, an excerpt of which appears below, under the headline "Published Analysis shows Mutai's Boston time not excessively aided"

Writing in this week's "Analytical Distance Runner," the official ARRS publication, chief analyst Ken Young wrote: "It should also be noted that Geoffrey Mutai (KEN) who ran 2:03:02 (in Boston), was ranked #2 on the ARRS competitive rankings and he had been ranked #1 for four weeks earlier in the year. When Haile Gebrselassie (ETH) set the current world record of 2:03:58.2, he was ranked #10 in the world. Hence, it is not surprising that Mutai could be capable of significantly bettering the world record. Too bad that he ran this on a course that is not eligible for records."

So they are estimating an improvement of 1:37 for the men, which is then apparently not significantly aided, this is judged according to criteria that anything improved by more than 5 seconds/km is considered excessively aided.

Very quickly, some thoughts on this to fill the Easter weekend break!

Using ranking to justify times

First off, the astonishing statement is that Mutai would be expected to significant break the record because he was ranked first in the world, compared to Gebrselassie who was ranked tenth when he broke 2:04. Well, perhaps they've forgotten that Gebrselassie was already the world record holder.  And that was only one year earlier!  So they can take that 10th ranking and lob it into a trash can, because he was only 26 seconds off the 2:04 barrier when he stood on the start-line, a year earlier, and therefore was totally expected to have a shot at beating the time.  Which he did, by 29 seconds.

Now, they're suggesting that a man ranked number 1 (and make no mistake, Geoffrey Mutai is pedigreed, and has "WR holder" written all over him), should break a record by 58 seconds given that his previous best was 56 seconds off the old one, but that he was ranked # 1...

That's poor inference if ever I have read it.

"Not excessively aided"?  The 5 sec/km implication

The next big claim in the article is that they estimate an improvement of 1:37 which they suggest is not excessively aided. Granted, that's their estimate of how much Mutai benefited, and one can argue that he naturally achieved this leap in performance (I'd argue very strongly against this), but there are a couple of issues.

First, the overall conclusion (and heading of the article) is flawed because 1:37 is a big difference to make if that is their estimate. To illustrate, it takes the time from being greatest ever by almost a minute, to making Mutai only 6th fastest performer in history, so I don't know how they arrived at "not excessively aided"...it's a huge difference.


The thing about that is they've set what is a very poor (and possibly arbitrary) cut off for "excessively aided" at 5 sec/km. I am not sure why they've chosen this size, but when was the last time we saw the marathon world record bettered by 3:30? (I can tell you the answer - it was Jim Peters in 1952).

And if we did see a WR beaten by 3:30, what would our reaction be? "Measure the course again", I suspect!  Imagine the 10k WR going from 26:17 to 25:27 in one run - we would think the guys had miscounted the number of laps and done 24 rather than 25!  The 5,000m record improved by 25 seconds?  When Gebrselassie broke it by 11 in 1995 is was staggering.

Now granted, I'm not sure whether the ARRS would apply their 5 sec/km principle to these events, but I'm illustrating the point - in a competitive sport with long history and access, performances at the level of a world record, in any event, are not improved by that kind of margin, ever.  The marathon world record will not fall by more than 3 minutes. (Of course, it's possible that the record in some trail run or small event is broken by the amount, but the key is the "strength and depth" of the event, which is a function of how many people do it, over how long and what quality they are.  The marathon is solid, it's too strong and too old for "weak records")


So while interesting, I think they have lost sight of the wood for the trees.  The first mistake is to look at the depth of the field, when really, the issue is the top, top level of runner.  The first five to ten men tell you what really happened, and they are the men who DO NOT improve by 5 seconds/km when already at the WR limit.  As I said, the WR in the marathon has not leaped forward by 5 sec/km in almost 60 years. 

In fact, since Dinsamo's record of 2:06:50 was bettered in 1998, SIX world records have been set, and the AVERAGE improvement has been 28.3 seconds.  That's 0.7 sec/km.  So a 5 sec/km margin might be fine for the masses, or even the near-elite, but for men trying to run faster than any human in history, 5 seconds per kilometer is, frankly, ridiculous.  And that's why a 1:37 "aiding" is massive!

As mentioned, this is the result of the method they use, which I don't think is very sound to answer this question.  That is, don't look at 43 elites, look at the very best in relation to the very best in previous years. So take a look at point 7 in this Letsrun.com recap of the week (the whole article is worth reading, in fact), because it presents that the wind had a very meaningful effect.  A record that stood for many years (from 1994) is bettered by Robert Cheruiyot, then bettered again in 2010, and then suddenly, seven men are faster than that, five of them by more than a minute.  That's excessive, in performance language, no matter what "stats" suggest.

The issue with statistics and meaningful differences

This is a classic case of whether statistical significance is more relevant than what is meaningfully different.  A lot of times in sports science research, studies will use statistical methods to conclude that a treatment or method (say for example altitude training) is not beneficial because it results in an improvement of say 15 seconds over 5,000m compared to a control group that for example did sea-level training.  And sure, there's a chance that these 15 seconds are down to 'chance' and thus not significant.  But equally, any elite athlete will tell you that "IF" they can find a 15 second improvement, they'll take it.  Most athletes will take an improvement of 5 seconds over 5,000m at the level of Olympic contender, because that's the difference between podium and back of the pack!

So there's a new method of statistics for sports science studies (and others, of course) where you now look for meaningful differences between groups.  And I can pretty much guarantee that a 1:37 improvement for an athlete who was already at 2:05 is going to be a meaningful difference.  Was it just a great day? Was it the wind?  I've expressed my view that at that level, the margins are seconds, not minutes, and so I think the wind had a big effect.

However, as we've said before, Berlin and Chicago will tell us, because if Mutai and Mosop are in the same shape there, well, let's expect at 2:03:00 again...but until then, I believe the statisticians are missing something!

Enjoy Easter!
Ross

Boston Wrap and looking to the Fall

Wrap up of Spring marathons and a build to the Fall

First off, thank you so much for your great comments to the last post I did on the Boston Marathon and the possible effects of the wind on Mutai's amazing 2:03:02.  The reaction has been overwhelming - the comments equivalent of a phone ringing off the hook!  As has become the norm, the discussion to the post is twice as good as the post, so thank you!  I apologize if I haven't been able to answer all the posts - I do read them, but things are rather busy here in Cape Town with the build up to the Two Oceans Ultra-Marathon this weekend!

With hindsight, and with the great discussion we've had on that post, I'd say that the one thing I didn't account for enough in the analysis of the history of Boston is the tactical nature of the Boston race compared to the fast, paced races of London, Chicago, Berlin.

Given that factor, I'd probably revise my impact of the wind to about 2%, which would place it around 2:20 to 3 minutes.  That would mean that Mutai was running mid 2:05 on the Boston course, which is perhaps a 2:04 or mid-2:03 pace anywhere else, and that of course is realistic for a man who is clearly among the best right now.  And like Mutai, there are a few men capable of that, in theory, which is what makes the Fall season so intriguing.

But the effect is not as low as one minute, or nothing at all.  Moses Mosop's coach, Renato Canova, has tried to explain the wind away, calling analyses "stupid speculation".  It is of course in his interests to coach a man genuinely capable of a 2:03:06, but I found his analysis full of holes, including the use of runners who ran slower than their PB as "proof" that the wind had no effect.   He then works out that on average, Boston 2011 was slower, and so the wind couldn't have had an effect.

This is completely nonsensical, because runners underperform relative to their best all the time - just ask Kebede in London.  Or Makau.  Or Lel.  Or Gharib.  Fact is, you set your PB over many races, as a result of the confluence of great training, great form, and a great day.  And when you compare one race to a history of races (especially the marathon, where it's not difficult to go two or three minutes slower - again, ask Kebede and any other marathon runner), you will almost always end up with this 'answer'.  Simply, there is too much variability in marathon running to make this analysis credible.  Performing beneath your own ceiling is not evidence that an advantage doesn't exist, whereas exceeding the ceiling MAY mean it does.  

There is also the very obvious oversight that not feeling a wind at all doesn't mean there is zero wind;  it means it's a tailwind equal to the speed of running.  Amby Burfoot observed this at the press conference, where most of the athletes said that they felt "no wind", which is perhaps the most telling observation of all.

There is also this justification that the wind switched around a lot and was sheltered by buildings.  Of course it would be, but you don't need a tailwind for 42,195 to have an effect, and no one is basing the calculation on a 20mph tailwind the whole way.  The physics calculations we showed assumed relatively low average tailwind of 14mph, equal, on average, to the speed of running.  The photo to the right suggests that it was, at times, greater, and I'm sure it would be lower at others.  But it was still a net tailwind, in the range of 12 to 18mph, and it had an effect.

In any event, the acid test will come later in the year.  Let's see if Mutai, Mosop and even Hall are able to reproduce anything close to their Boston performances without the wind, even on flatter courses. 

I thought I'd wrap up the Spring Marathon seasons though, and chat about the women's race, which was yet another one of the ages in Boston, and then look ahead to the Fall, and what may happen there.

The women's race, one for the ages

It got lost in the discussion about the wind, but yet again in Boston, the women's race produced a great duel all the way to the finish line.  It was reminiscent of the Wanjiru-Kebede duel in Chicago last year, where those two champions surged and counter-surged in what was more like a bicycle race than a marathon finish!  This time it was Caroline Kilel and Desiree Davila who raced it out.   You can read our Live post here for the "play-by-play", surge by surge account of what was maybe the best race of the Spring marathon season

Neither would have been a recognized favourite before the race.  Those went by the wayside very early - defending champion Erkesso was out of it within the first 20km, and then Dire Tune, maybe the big favourite, was dropped soon after 30km by a pace that, it has to be said, wasn't all that fast.

Then it was left to three.  Sharon Cherop, Davila and Kilel.  None had spectacular credentials - Cherop was the fastest with a 2:22:43 last year, while Kilel, aged 30, had a 2:23:44 to her credit.  Davila, meanwhile, has been improving consistently, but with a PR of 2:26 would perhaps not have been expected to outlast those around her.

That she did though, and she was the aggressor for much of the second half of the race.  In an amazing display of courage, she took the race to Kilel and Cherop and there were times when the elastic between her and the two Kenyans was stretched.  But it never broke.  Kilel was able to cover all the surges, and the three entered the final 2km together.  Cherop would eventually be dropped, and Davila seemed to have run her race when a gap of 5 m appeared and Kilel seemed to be pulling away.

But Davila dug deep, caught up and then counter-surged one last time.  It was spectacular racing, full of guts, but in the end, Kilel had answers and won by a margin of two seconds.  Cherop was only four seconds further back.

It was the fourth time in a row that Boston has produced such an epic finish.  The victory margins in the last four Boston races have been 2, 1, 3 and 2 seconds.  Average margin of victory since 2008 is two seconds! And so if it's competitive racing you want, Boston seems to have something that produces it among the women.

The impact of the wind on the women

As for the times, collectively, the women ran faster than ever in Boston.  Margaret Okayo's course record of 2:20:43 (2002) survived, but PRs didn't, and the depth of the fast times says a lot about the day.  A few people have written in to say that the women's result suggests that the wind wasn't that bad, but here are some numbers:

• The winner was fourth fastest in the history of the race - only Okayo's amazing run survived, along with Ndereba's, who was second that day in 2002, in 2:21:12.  The third best time of Uta Pippig came in 1994, when the wind was blowing almost as strongly as on Monday.  Some estimated that the wind that day was worth 3 minutes to Pippig
  
  
• Davila's time was the fastest ever by an American woman
  
  
• The top 5 all ran PBs - Kilel, at 30, and with 11 marathons in her resume, broke her PB by just under a minute.  Davila hers by almost four minutes, Cherop by a few seconds, and then fourth was Caroline Rotich who set a new PB by about 5 minutes.  Kara Goucher in fifth was over a minute faster.  
  
  And yes, one or two runners will always have great days, with breakthroughs or big improvements (because their previous best might have come from a tactical or hilly race like NY), but four out of the top 5 improved by margins rarely seen at this level.  And key is that everyone was way faster in Boston compared to previous Bostons 
  
  
• Overall, the times were faster than ever.  Davila and Cherop finished within six seconds of the winner, and so I believe the average of the top 3 was the fastest in history.  The other super-fast run was in 2002, when Okayo broke the record.  On that occasion, Ndereba ran 2:21:12 to finish second, but the third placer was a 2:26.  This time, the top six broke 2:26 and so it was deep and fast

The other thing about the women's race is that it started very tactically.  Kim Smith was almost a minute clear within 15km.  By halfway, that lead was 50 seconds.  But she wasn't really going that quickly - her split at the half was 1:10:52, and the main group was almost a minute behind with a dozen women in it.  So there's no question that the women started conservatively, much more than the men, and the overall time reflects that.

And finally, I don't think this women's field is nearly as strong as what was seen the day before in London.  Where would Kilel, Davila and Cherop ranked in a race with Keitany, Shobukhova and Kiplagat?  If you say top 3, I'd challenge you on that.  Simply put, this was not a super strong field, yet they ran times rarely seen in Boston.  As a final word, the wheelchair races were also super quick.  The women's course record was broken - the previous record, you shouldn't be surprised to learn, was set in 1994, the very windy year that saw both men's and women's course records.  The men's race was the second fastest ever, and it came down to a three-way sprint.

Looking to the Fall - the anticipation builds

The upshot of all this (including the debate) is that we have a magnificent fall marathon season to look forward to.  Two Mutais, one a winner in London, one in Boston.  Emmanuel produced a 28:44 10km stretch to break a field that included Makau, Kebede and Lel.  Geoffrey produced a 28:15, albeit wind-assisted to run a minute inside a world record.  And so did Moses Mosop, for that matter, in his debut.  Improvement with experience...?

Still to join the 2011 year is Sammy Wanjiru.  Tsegay Kebede underperformed in London, but he'll be back, no doubt.  The Berlin and Chicago races later this year will produce huge racing between what is now one of the deepest and highest quality groups of marathoners ever seen.

Will Boston 2011, 2:03:02 change those races?  There is a school of thought that the mindset of the elite will be changed by this, that 2:03 is the new 2:04, and that they'll be more aggressive, more willing to go out in 61:00 to 61:30 for the half.

It will certainly be fascinating to see how the elites structure the races.  There's no question that there are currently four or five guys who have the capacity to break the 2:04-barrier.  Mosop, Mutai, Mutai, Wanjiru, Makau, Kebede.  Plus one or two others who've not yet had the opportunity.  Will they go out in 61:30, inspired by the belief that a 2:03 is possible?  They may, but I doubt it.  I think it's more likely we'll see the target at 61:45 to 62 at halfway, with the hope that one of these guys can hang on in a 62 to break the world record.

I'd love to see the 61:30 or so at halfway.  My hypothesis at this stage is that if they do, they'll blow in the second half, and run a 63, at best, missing the world record.  At that level, with things not being absolutely perfect, 1 second per kilometer too fast is, well, too fast, and so expect incremental changes, not the kind of radical leap that Boston produced.  And speaking of perfect, it will need absolutely perfect conditions as well - too warm, too gusty, record gone.

Bring on the Fall!


Ross


P.S.  And lastly, here are two videos from the race, showing women's top 3 at 300fps about half a mile from the finish line.  Great footage at slow speed, and its interesting to note the mechanical differences between Davila, Hall and the Kenyans.  Food for thought...?

A 2:03:02. 3 to 4 min? What effect did the wind have?

2:03:02 dissected.  What effect did the tailwind have? 3 to 4 minutes...?

I don't know the answer to that question.  Let me say that right upfront.  It's insoluble.  But it's too intriguing not to ask, and attempt to answer, and there are a few approaches to it to shed light on a  quite remarkable Boston Marathon, now that the wind has died down and the dust settled on the fastest two marathons in history. Just where do Geoffrey Mutai's 2:03:02 (and, for that matter, Moses Mosop's 2:03:06) rank in the history of marathon performances?

Not a recognized record - why not?

As you'll know, Mutai's record will not be accepted as the official world record.  The main reason is that Boston is a point-to-point course with an overall drop in elevation greater than 1 m per kilometer, a one in a thousand drop (Boston drops by 135 m).  Also, a second criteria for course eligibility is that "The start and finish points of a course, measured along a theoretical straight line between them, shall not be further apart than 50% of the race distance".  This would apply to Boston, because the course is basically a straight line running north-east, and that is why a south-westerly wind, as we saw today, would have such a profound effect.  The image below (click to enlarge), again taken from Letsrun.com in their preview, shows this nicely.  The wunderground.com site had the wind at 14mph westerly, incidentally.

So not recognizing Mutai's time is indirectly influenced by the wind (as indicated by that second clause which would help to prevent a 'wind-aided' record), but it's mainly because of the drop, despite the fact that Boston is actually a slower course than the other Majors, as we'll see below.  But the real meat of this debate is the effect of the wind on the times?  And what would Mutai have run on any other course?

Let's repeat that this question is unanswerable.  We will never know exactly what Mutai would be capable of on a flat, fast course like Berlin or Rotterdam on a still day.  We will never be able to quantify the improvement that might have occurred thanks to the tailwind during today's race.

Equally, we will never know how much Boston's relatively tougher profile, with its Newton Hills in the second half, costs runners compared to the flat and fast courses in Europe and Chicago.  So to ask "What could Mutai have run in Berlin?" is a rather futile exercise.  I know this, and so this is somewhat speculative.  But it's also an intriguing one, and there are some analytical approaches that one can take to help remove guesswork and rather be informed speculation!  And that is the purpose of this post!

So, what effect did the wind have on Mutai, Mosop and co?

The mathematical approach - drag, wind resistance and improvement

I must confess this is not my first approach to the problem, but it is the best one.  My first approach is physiology and the physiological variance in performance, combined with historical context, as you'll see below.  But if you have the physics, then this approach brings some objectivity.

The two problems with this are that you need to make some assumptions about how to treat the runner - a cylinder with a given drag, and an assumed mass and height.  Also, you cannot always know that the wind is from behind, and nor do you know its speed the whole way, so there are estimates, but I still feel you still get valuable information given the length of the course, provided you make valid inputs.  It gets us into the ballpark.

So thanks to djconnel and Giovanni Ciriani for their inputs on this, which I'm pasting directly below:

Assume a human is 1.7 meters tall by 40 cm wide, with Cd close to 1 for a cylinder with normal wind incidence.  That's CdA = 1.5 meters squared.  Then assume the wind is blowing at around 2 m/sec (very fast for road-level given how fast these guys are running) with an air density near 1.2 kg/m-cubed.   That's 6.25 N = 6.25 kJ/km.   Minetti measured close to 3.4 kJ/km/km for running: http://jap.physiology.org/content/93/3/1039.full.  So if a runner weighs 60 kg, that's 204 J/m, of which the tailwind is saving 6.25 J/m, which if speed is proportional to power, is 3.8 minutes saved. (courtesy djconnel).   

 So that's 3 min and 48 seconds.


And then there is this, the wind resistance and relative velocity argument:

Aerodynamic drag for a runner is about 3% of forces acting against him/her. Today's wind in Boston (according to wunderground.com) was 14 mph W to E, which is just about the same speed the top runners were running at. Therefore the runners didn't experience aerodynamic drag. Since their power output remained the same, a 3% advantage translates directly into a 3% higher speed, and a 3% lower time = 3 min and 36 sec. (Courtesy G. Ciriani)

I'm going to work with an engineer to see if it's possible to refine the assumptions a little and work towards a clearer understanding of the physics.  However, we're in the ball park of 2 to 3%, 3 to 4 minutes.  Now, let's compare that to performance variations.

Historical approach.  Understanding the context of performance, Boston vs other marathons

I'm a big believer in history, as it applies to performance.  That's both "institutional history" and individual history.  Historical context is important, because it points to what should be expected in terms of improvements in performance.  Outliers happen, yes, like Bob Beamon almost jumping right over the pit in 1968, but when this happens, there is often an explanation, or at least part of one.  That's the value of context.

And so when you have an outlier, historical lessons become even more valuable.  2:03:02 is an outlier, because it's almost a full minute faster than the current record, and it was achieved on a course that is generally recognized to be slower than the other big city courses (with the exception of NY).

So the first way to examine the effect of the wind on Mutai's performance is to ask how large an outlier it is for the Boston course specifically?  The graph below shows the winning times in Boston since 1990.

The average winning time, excluding today, is 2:09:20, and interestingly, in the last TEN years since 2000, it has been 2:09:30.  Boston is one of the few major marathons where times have NOT plummeted in the last decade.  If you would rather compare Mutai to the best ever in Boston, then the previous record, only one year older, is that of Robert Cheruiyot, at 2:05:52.

So Mutai is 6:18 faster than the average and 2:50 faster than the next best time in Boston's history (with the exception of positions 2,3 and 4 in the same race, of course!).  It's important to start with Boston-comparisons only, because as we'll see shortly, Boston cannot be directly compared to London, Chicago or Berlin without some correction for Boston's hills and slower course.  What is more, the top four today all bettered the previous fastest Boston time by a considerable margin, since Hall finished in 2:04:58 to claim fourth.

Clearly, the wind had a significant effect on today's times, unless you believe that Mutai is genuinely a 2:03:02 guy in Boston, and by extension, that Mosop is at the same level, two minutes faster than the next best ever.  You also have to believe that Hall is a 2:05 or faster runner on a hilly course (which many feel doesn't suit him).

And remember, these are all Boston times, and the flaw in the argument becomes apparent when you consider how "slow" Boston is compared to other big city marathons, as shown below:

So Boston "expects" to be 3 minutes slower than the big European races (Rotterdam is as fast, incidentally - we just don't have the times going back 10 years), and 2 minutes slower than Chicago.  Recall that London has been won in 2:05:10, 2:05:19 and 2:04:40 in the last three years.  Berlin - 2:03:59, 2:06:08 and 2:05:08.  Boston?  2:07:46, 2:08:42 and 2:05:52.  Cheruiyot's sub-2:06 brought that down last year, the gap was 1 minute (I don't know the wind conditions then though), but generally, it's 3 minutes or more (Yes, there are years where Boston is super slow, and there are years when it is much faster, but last year, the 2:05:52 was the first time ever that Boston was within a minute of the other races.  So I don't think it's unreasonable to view Boston as slower)

Mutai vs Boston vs flat courses

This helps us understand where Mutai's performance ranks.   If you believe Mutai is a 2:03:02 man in Boston, then you're either saying that hills don't affect him, or that he could be a 2:01 performer or better in London and Berlin!  So we have something of a circular argument, it has to be said.  If you believe that Mutai is genuinely 2:03:02 material, then you can dismiss the impact of the wind.  But if you believe him to be a 2:05 runner, maybe 2:04:00 on the right day, then you have a wind impact of between 1 and 2 minutes COMPARED TO A FLAT COURSE.  Now add the Boston "disadvantage" due to hills and the wind is again coming out to 2 to 4 minutes, depending on how much Mutai may have been affected by the hills.

The point is, it's not valid, under any circumstances, to compare Boston times to those of London or Berlin.  Normally, it's for the opposite reason - Boston is slower.   Today, it is the other way around, and that is significant because it helps us understand just how big an effect that tailwind might have had.  In other words, the wind was at least sufficient to overcome a historical difference of 2 to 3 minutes on these other races. 

But Boston is now a minute faster - the wind was responsible for overturning a 3 minute deficit and turning it into a 1 minute advantage.  The wind is therefore estimated to be worth 4 minutes, based purely on historical averages (note that this approach assumes equality of strength of the races over the years, as well as the quality of the athletes at the top - I think this is a sound, valid assumption given the short three to five year period, others may disagree.  Certainly, there was a time when Boston attracted "lesser" runners, but the last five years have been comparable to London, Chicago, Berlin)

If one makes the admittedly tenuous leap that Boston is around 2 to 3 minutes slower, then this 2:03:02 in Boston is worth a...better than a 2:01 in London.  Only an extreme optimist would suggest this, and that's partly because we understand that such dramatic improvements don't happen, and because we know the characters.  So next, we need to look at Mutai, Mosop, Hall and co and ask if these individuals are running "out of character"?

Within runners - an error-prone comparison, but valuable with interpretation

Comparing the same runner in two different events can be fraught with danger, but if you are sensible, there's valuable information there too.  The reason for this is physiological variance - elite runners at this level can have bad days, where they are minutes off their best (Kebede in London may be an example of this.  Cheruiyot yesterday is another).  But when they have great days, they don't go minutes faster.  If you are an elite (and by this, we're talking top 20 ever), you don't leap forward by minutes in one race.  That happens to a Keitany, who has run a "slow" marathon in New York on debut, and then blasts 9 minutes faster in London.  That's not that unexpected, given the context.  But for the already established elite, there is such a thing as "acceptable physiological/performance variance".

So we accept the limitations, but use this to give more context to the physics and the history that we've already discussed.  

Let's take Mutai.  He has shown his marathon credentials on the fast, flat European races, first by running 2:04:55 in Rotterdam, and then 2:05:10 in Berlin.  To improve by 1:53, on the toughest of the three courses, that's a huge improvement.  And yes, runners have breakthrough days, but that margin is too large to simply be a "good day".  At this level, once you're in the top 10 in history (which Mutai was even before today) improvements of 20 seconds are remarkable.  Gebrselassie has set two world records, one by 29 seconds, the next by 26.  Those are breakthroughs for this caliber of athlete. 

1:53 is thus artificially high.  So assume that Mutai was in the same condition as Rotterdam and Berlin, when he ran very close to 2:05 both times.  Then, in Boston, he runs 2 minutes faster on a course that is normally about 2% slower than other courses.  If you assume that Mutai was in great shape, 30 seconds faster than Rotterdam (a huge leap forward in performance), then you still have the wind helping him to the tune of 1:30 compared to a flat course...

Knowing your history and where Boston lies, you know have the worst case where you have to also add time for the Boston profile.  2 minutes?  That's a conservative estimate based on history?  Then suddenly you have between a three and four minute difference made by the wind.  I suggested this in my first write-up after the race, and the physics calculations (assumptions and all) support the estimate - 2 to 3%, 3 to 4 minutes.

To return to the earlier example, if you believe the wind was worth only 1 minute today, then you're effectively saying that Mutai is a 2:04 guy in Boston, which means a 2:02 or better performer in London or Berlin (1 to 2% faster).  Either that, or that he is "immune to hills". 

The same is true for Ryan Hall.  A 2:06:17 runner, Hall has raced the marathon numerous times.  In his case, you have two Boston performances to compare to - a 2:09:40 and a 2:08:40.  Maybe Hall continued his improvement and was in 2:08 or even 2:07:40 shape this year.  He still ran a full 3 minutes faster than this. 

Of course there is variability in performance.  Athletes improve, they get worse.  But by seconds, not minutes in this population, and a three minute improvement, suggests to me close to a 3-minute impact by the wind, if not more. 

For an illustration from years gone by, the last time we had such strong tailwinds in Boston was 1994.  That year, Cosmos Ndeti won the race in a course record that was bettered by only two men until this year (both Cheruiyots, one in 2006, and last year).  Now there are four men going under 2:05 in one race.

But back in 1994, America's Bob Kempainen produced a "Beamonesque" performance by running 2:08:47, which was an American record at the time, and would remain so until Ryan Hall broke it.  Kempainen was a good, but not great runner, and his next best time was 2:12:45.  That's a 3:58 improvement, on the tougher Boston course, thanks to a windy day like we had today.

Yes, there are factors that influence this, which is why his numbers alone don't make this case. But when you have Boston's history, plus the comparison between Boston and other races, plus Mutai and Hall's recent racing credentials over Boston AND other courses, then a picture starts to come into focus.

The pacing and 2:03:02 performance in context

So how big an effect did the wind have?  Impossible to say.  Can we conclude that the wind was worth about 3 to 4 minutes? 2 to 3%  I suspect so.

And so while Mutai's time is exceptional, I would interpret it differently.  2:03:02 is superb running - on the hills of Boston, wind or not, it defies belief.  A second half of 61:05 is eye-popping.  But if that wind is genuinely worth 2 to 3%, as I suspect, then the first half of 61:57 is actually worth about a mid-63 minute first half.  In other words, conservative.  That suddenly explains the searing pace in the second half, and it also helps us understand those final 10km.

The final 10km are also mostly downhill and so a 28:25 is extra-ordinary, but with a wind of even 2% (conservative), plus a relatively physiological "conservative" start, and the ingredients were there for a super fast finish, and an amazing overall time!

I guess we'll never know, but we have a great fall marathon season to look forward to!

The fall marathons and the impact of Boston

What will be fascinating is to see how this impacts the Fall marathons, particularly Berlin.  It's like that Geoffrey Mutai will race there.  Maybe even against Emmanuel Mutai.  And Wanjiru.  Will the elite men, having now touched the 2:03 barrier try to go out in 61:30 for the first half?  That would be faster than Boston's first half, without the downhill start and the following wind, so it's adventurous, but does Boston 2011 change the mindset of the elite?

And if the top men, in a race, do go out in 61:30, or even 61:15, will that pace be sustainable?  That's a fascinating question, and it sets the fall marathons up in a big way.  Remember that until yesterday, only Haile Gebrselassie and Emmanuel Mutai had broken 62 for the second half of a major marathon.  Now we have Geoffrey Mutai and Moses Mosop.  Is that possible with a 61:30 first half?  My initial thought is that a first half of 61:15 to 61:30 is just too quick, for now.  61:45, followed by a 62 min is doable, if the weather conditions are perfect in Berlin, perhaps.

But that's all conjecture - let's wait for October to see!  Marathon running has never been healthier!

Ross

P.S.  A late addition to the post. In the discussion to the previous thread, we received a comment from Mike with this link to a running calculator based on Jack Daniels' formulas for pace.  In this calculator, if you assume that the wind was 14 mph tailwind, then the predicted time with zero wind is about 2:10.


There are clearly differences in how the wind is assumed to impact performance!  And our 2 to 3% conclusion in the post above, aided by the physics of some readers, seems to be on the conservative side!  I suspect that this calculation is "idealized" and what you'll probably find is that the variable wind speed and direction in "real-world" Boston conditions, combined with shelter, combined with the different physical stature of runners, accounts for differences.  But overall, I'm pretty confident (but never certain) in the estimation of 2 to 3%, or 3 to 4 minutes thanks to yesterday's wind in Boston.