003.012 Elite Distance Free Events are Asymmetric

In a previous post entitled “Sectionals, Futures, and Junior Nationals”, we analyzed the qualifying times for those elite USA-S senior championship meets.  Our analysis revealed an systemic asymmetry in the distance Freestyle events, namely, that it was easier for women to qualify in the 800 Free than the 1500 Free, while it was easier for men to qualify in the 1500 Free than the 800 Free.  We also learned that the 800 Free qualifying times were unfair to men while the 1500 Free qualifying times were unfair to women.


We speculated that this asymmetry might be a legacy of the pre-2020 Olympics, where women could swim the 800 but not the 1500 and men could swim the 1500 but not the 800.  In this post, we’ll summarize the statistical evidence for this asymmetry and argue that USA Swimming should adjust the qualifying times for it’s elite meets to reflect the current Olympics reality, namely, that men and women will swim both distance Free events at the 2020 Olympics.

A Brief History of Distance Freestyle at the Olympics.

In 1904, men first swam the 1500m Freestyle event at the Olympics.  In 1968, women first swam the 800m Freestyle event at the Olympics.  For every Olympics from then until 2016, women have been excluded from the 1500 and men from the 800.  On June 9, 2017 the International Olympic Committee announced that the 2020 Summer Olympics will be the first Olympics where men and women will swim both distance freestyle events.

Technical Background.

Please review our prior posts entitled, "The Fairness of Qualifying Times", “The Fairness of Open Events” and “Sectionals, Futures, and Junior Nationals” for technical background.

USA Swimming Favors the 800 Free for Women.

It’s easier for 18/Under women to qualify for the 800 Free than the 1500 Free in the 2019 Sectionals, Futures, and Junior Nationals.  The acceptance likelihood is the relative fraction of all 18/Under women who achieved the event qualifying time in a recent swim.


Plotting the ratio of the women’s acceptance likelihoods for the two events reveals that it’s more than 1.4 times easier for women to qualify for the 800 than the 1500.


USA Swimming Favors the 1500 Free For Men.

It’s easier for 18/Under men to qualify for the 1500 Free than the 800 Free in the 2019 Sectionals, Futures, and Junior Nationals.  The acceptance likelihood is the relative fraction of all 18/Under men who achieved the event qualifying time in a recent swim


Plotting the ratio of the men’s acceptance likelihoods for these events reveals that it’s 1.1 to 1.5 times easier for men to qualify for the 1500 than the 800.



Since it’s easier for women to qualify in the 800 than the 1500, and easier for men to qualify in the 1500 than the 800, these distance free events can’t be gender-fair.  To quantify the fairness of an event, we’ll use weighted acceptance likelihood ratios as described in “The Fairness of Open Events”.

The 1500 Free is Unfair to Women.

Plotting the men’s effective acceptance likelihood in the 1500 divided by the women’s shows that it’s 1.3 to 1.4 times harder for women to qualify for the 1500 than men.



The 800 Free is Unfair to Men.

Plotting the women’s effective acceptance likelihood in the 800 divided by the men’s shows that it’s 1.1 to 1.5 times harder for men to qualify in the 800 than women.



Across all three meets, the 1500 cuts are more unfair to women than the 800 cuts are unfair to men.

Proposed Remedy.

Given the long history of gender-asymmetric Olympic distance freestyle, it is not surprising that USA Swimming would bias qualifying times to discourage women in the 1500 Free and men in the 800 Free.  However, given the June 2017 IOC announcement that men and women would henceforth be swimming both distance freestyle events, USA Swimming must now eliminate the systematic gender asymmetry in its distance freestyle qualifying times.


The principle remedy is for USA Swimming to raise the qualifying times of the women’s 1500 Free and the men’s 800 Free in all three championships, as soon as possible.