It's gotta be the suits (world records in swimming)

Ryan Lochte is smiling, but what about everybody else?

I am suffering from a bit of Olympics withdrawal, and getting quite a bit of pressure from someone, so I thought would write one more thing about an Olympic sport before they go away for four years.

Setting a world record in swimming is extremely tough these days. At the 2008 Summer Olympics in Beijing the eight 100 meter events (Free, Back, Breast and Fly for men and women) saw six world records set – three in the Men’s 100 Free alone. By comparison the 2012 London games witnessed only two world records in the same set of events. Factor in the 4x100 relays (Medley and Free) and the 400 IM and Beijing gets an additional six records for a total of 12 while London sees only two more to bring the total to four.

Of course back in Beijing swimmers could wear full body suits made of polyurethane, reducing their drag relative to bare skin and providing buoyancy. In the summer of 2009, as swimmers were setting records by the poolfull (get it?) at the World Championships in Rome, swimming’s governing body banned the suits effective January 1^st 2010.

So what has all this done for the state of swimming world records? Were these suits responsible for the success or have swimmers found new ways to train that make those records achievable.

How does this normally work?

Going back to those 14 events that I mentioned earlier, I compiled the set of records going back to 1960 (except for the Men’s 100m Breaststroke, for which 1961 is the earliest record I could find). Then I plotted these performances against each other normalized to a scale where 100 equals the record as it stood 1/1/1960.

For the next 48 years these records tended to move in a relatively similar pattern. While there were jumps at various points throughout, the endpoints for each record pair (men’s and women’s record in the same event) are remarkably similar.

How screwed up is it now?

Fast forward to the next two year cycle and suddenly there is some significant movement. Records that had been flat for years or even decades jumped downward by several percentage points.

By the time the swimming world came to its senses about this, literally every one of the 14 records in the data set had been broken a minimum of two times. In the two years of the suit era these 14 events saw 42 new records. In the two and a half years since they have seen four.

Where are the next records?

For swimmers looking to snag a world record, this does not look promising. The place to look is at those events with the least improvement during the suit era. If the suit era helped them least, it pushed them off their trend the least. The table below shows the proportion of improvement since 2000 that happened during the suit era:

Based on this table, the Free and Back events may be out of reach for a while. The suit era provided these swimmers with much more advantage than those in the Fly or Breast, with well over 50% of the post-2000 improvement happening in just 17% of the years. Of the four records set since the suit era in these 14 events none have been in the 4x100 Free or the 100 Free or Back.

Expanding out to all of the long course world records, nine out of 40 events have records set since 1/1/2010. Only two have been in the Free or Back: Sun Yang in the Men’s 1500m Free and Missy Franklin in the 200m Back.

All of this serves to prove that it really was the suits and Missy Franklin is a pretty good swimmer. It’s a good thing I have all these numbers to figure this stuff out.

In case you were wondering, this is a video of the US Olympic Swimming team performing Call Me Maybe: