Alan brought up the suspicion to Ye’s world record in women 400 metres individual medley. And I quote:

“Her last split caused controversy (deep suspicion of doping) as she swam it faster than the fastest male swimmer. I wonder how commonly this occurs in swimming. In running the numbers are well known: the convergence of male/female marathon times, for instance (stuck since Paula’s best run). Is the female/male ratio always close to one in swimming? How does it depend on distance?”

In his reply, he suggested to compare Men’s records with Women’s. I think this is a good idea. So I present another world record progression in both men and women 400-metre medley. The following is the snapshot; click here for the interactive chart.

It seems that the distance between the Men’s world record in 400-metre medley and the Women’s has become more divergent since 1990s. The least distance is 0.27 min around 1983. Recently, after Phelps greatly shorten the Men’s record, the distance become larger. Even when Ye broke the Women’s record, it’s still 0.41 min, obviously bigger than that in 1980s. Honestly, I don’t know how the suspicion has come around; but I remember when Phelps broke his record in Beijing 2008 Olympics, he received applause and flowers.

Another interesting finding: in Montreal 1976 Olympics, Strachan and Tauber broke both the world records, and in Beijing 2008 Olympics, Phelps and Rice also broke both the records.