Boston Elite Field 2015

Last year I posted about how chances of a non-African country winning the Boston Marathon seemed to be good because of the widening interval of winning times (more recently there had been some historically "slower" races and some historically "faster" ones) and this actually happened.   Meb Kflezighi ran a remarkable race and was widely celebrated as he represented the US in a race more recently dominated by African countries.  His time for winning the race was obviously the fastest, but others in the field had faster PRs.  Because of the variation in winning times my conclusion has been that this provides opportunities for certain runners representing non-African countries to contest the race well.

The amount of participants from Africa in the elite field clearly increases the likelihood that the winner represents an African country.  The runners in the elite field mostly fall into or below the confidence interval shown in the graph above with the slight exception of Matt Tegenkamp whose PR for the marathon is 2:12 ish, just above where this statistical measurement would encompass.  It is clear that once again the elite field is dominated by African runners who are putting up some really impressive PRs.

And yet, with the difference in PRs, last year there was a similar dynamic.  Dennis Kimetto comes to the race with a 2:03 PR and Meb Kflezighi wins the Boston Marathon having run a 2:09 PR previously.  Thus we have another great story this year.  Incredible athletes, some of whom have in the past run much faster than others.  And yet, who can tell what will happen race day.

But why try?  Why did Meb think he could beat someone who in marathon terms could go somewhere he could not?  More broadly, why do we love these events?  Why should Matt Tegankamp attempt to rival someone who would be 2 miles ahead of him on each of their best days?  Variance.  Within these elite athletes there is the notion that on any given day, the guy next to you could be at his best or worst.  As spectators, we're drawn to variance...we love possibilities of things not turning out predictably, or that there is variation in what we assume to be true.  Athletes place their hopes in this, that they could run their absolute best and others may not.  Confidence intervals tell the story of variance, that statistically we can't know for certain.  I think this year yet again, we could see this same variance play out.  The athlete that doesn't have the fastest PR runs their best despite the odds.  This is what makes a great race and what we could see again tomorrow.

Boston Marathon Winner

In a previous post I described the current level of competition between countries/continents in the marathon and specifically the Boston Marathon.  The dominance of Africa in the marathon was discussed at length and recent times for the winners of past Boston Marathon events were shown as the times descended and the winners were represented by African countries.  It was also mentioned that recently, the range of expectation has changed to where I thought it would allow an athlete representing a non-African country to win the race.

Monday this came true.

Meb Kflezighi (USA) won the Boston Marathon and set a personal record in the process (not bad for an almost 39 year old).  There are a couple of interesting things about his win in the Boston Marathon that I think allow for a shift in the way spectators and participants view this race.

Expectation
As can be seen in the graph below, spectators and runners alike had a mutual understanding that of all the countries represented the chances of a non-African country winning were slim from the sheer numbers of African runners that can run the kind of times needed to win.  Meb's win changes that expectation for participants who on their best day could run in the 2:07-2:10 range.

For spectators, it allows for a shift in understanding about the variance in races.  Seven of the runners in the elite field had run a marathon in under 2:05.  Relative to the potential of the field and past times, the race this year was not run remarkably fast at least for these athletes.  As can be seen below this time was very comparable (within 1 minute) of the last time this race was won by American Greg Meyer in 1983.

In 1983 Greg Meyer ran a race time that was faster than what could be "expected" to win the race at that time ("expected" that is within the confidence interval).  30 years later our expectations change again where the times of 30 years ago can win races.

I think variance in this regard is healthy for the interest in a sport.  It increases the interest of spectators because the possibilities are more wide-ranging and (arguably) the race is more entertaining.  It provides hope to all marathon runners who can run times within what could be "expected".  Meb's win also provides inspiration across age groups who may have seen running as a mid-20s to early 30s sport.  This next year's Boston Marathon will no doubt see a very competitive field like previous races.  The shifting expectations about this race will hopefully lead to increased participation from athletes and heightened interest by spectators.    

Boston Marathon Winners and Challenging Africa

The marathon is dominated by African runners.  David Epstein in a relatively recent interview mentions about a specific tribe in Kenya called the Kalenjin, "There are 17 American men in history who have run under 2:10 in the marathon...there were 32 Kalenjin who did it in October of 2011". The times and number of African runners reaching those times times rarely achieved by their racing counterparts is impressive.  Below is a graph showing the top 50 times recorded by Association of International Marathons and Distance Races (AIMS) over the past few years.  

The Boston Marathon is perhaps the most sought after race for marathon distance runners.  At least in the US, qualifying for the Boston Marathon can be the pinnacle achievement for an avid runner's career.  As one would expect, this race draws runners from all over the world who seek the prestige and purse of winning the Boston Marathon.  Over time the winners of this race have changed, as arguably, the physiology (and arguably culture) of runners has become more of a factor since access to the race has become easier over time (for more on Kenyan physiology and culture as running determinants, see this Radiolab podcast).  Like in all marathon races, the times are getting lower and African runners have shown a clear dominance over the last several years.  In the graph below you can see the descent into Boston Marathon winning times that 30-40 years ago were unimaginable.  

 
Here are the same times and years broken out by continent instead of country.  Notice the break in dominance of winning this marathon from Europe/North America to Africa in the mid 1980s.  Prior to this time, the race enjoyed a larger amount of variety in countries/continents winning the race.

The grayish line intersecting these points is basically a confidence interval (95% confidence interval).  One could interpret any point within this grey area as a time that would not be a statistical outlier or a time that could be expected to win the Boston Marathon.  The interesting thing about this graph is how the gray area is now widening in the past few years.  This is partially because of the fastest marathon ever run is included in this graph (This was done by Geoffrey Mutai in 2011, which did not count as a world record formally because of the change in relief of the Boston Marathon).  Notwithstanding this time, we also see times more recently that have historically been run by North Americans, Australians, Asians, and Europeans.  Though it is clear that Africa demonstrates clear dominance in this marathon and others, the times that African participants have been running are not insurmountable from a historic perspective.

This "widening" of race time expectations I believe provides opportunities to continents and countries who have run races at this speed in the past.  The question now becomes how many runners in these continents/countries can currently run at these paces.  There are some.  Both Ryan Hall and Dathan Ritzenhein are US runners who have run marathons in 2:08, which would make them both very competitive with the recent winners of the Boston Marathon.

Stripping out the African countries we can see the times of other continents over the past several years.  In fact all of these times fit into the range of "expectation" (95% confidence interval) of the most recent races.

Running this fast a race must take into account multiple other factors such as weather, injury, etc.  However, based on the data of previous races, the times produced by these runners in the graph above would have been very competitive if not won previous recent years' marathons.  There may not be as many challengers in other continents, but those challenging African runners stand a chance.  More recently if a non-African runner had run the Boston Marathon in what would possibly have been their best race, they would have had a great chance at winning.