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 Swimming long course championship meets.  Our analysis revealed an systemic asymmetry in qualifying times for the long course distance freestyle events, namely, that it was easier for women to qualify in the 800m freestyle than the 1500m freestyle, while it was easier for men to qualify in the 1500m freestyle than the 800m freestyle.  We also learned that the 800m freestyle qualifying times were slightly unfair to men while the 1500m freestyle qualifying times were very 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 freestyle 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.

To analyze the difficulty of making a cut, we’ll use our historical database of 23 million USA-S age group swims to calculate athlete acceptance likelihoods.  The acceptance likelihood for an event is the number of USA-S athletes in the event’s age range that swam at least as fast the the event’s qualifying time, divided by the total number of USA-S athletes in the age range.  The 800m and 1500m freestyle are only recognized for 11/over athletes, so the acceptance likelihood calculations for these events is limited to USA-S athletes aged 11 to 18.


Please review our prior posts entitled, “The Fairness of Qualifying Times”, “The Fairness of Open Events” for technical background.  The posts entitled “Sectionals, Futures, and Junior Nationals” and “2020 U.S. Olympic Team Trials” contain analyses of those elite USA-S championship meets.

USA Swimming Favors the 800 Freestyle for Women.

It’s substantially easier for 18/Under women to qualify for the 800 than the 1500 in Sectionals, Futures, Junior Nationals, and Olympic Team Trials.


Plotting the ratio of the women’s acceptance likelihoods for the two events reveals that 1.3 to 1.5 times as many 18/under women are expected to qualify for the 800 than the 1500.


USA Swimming Favors the 1500 Freestyle For Men.

It’s easier for 18/Under men to qualify for the 1500 than the 800 in Sectionals, Futures, Junior Nationals, and Olympic Team Trials.

Plotting the ratio of the men’s acceptance likelihoods for these events reveals that 1.1 to 2.0 times as many 18/under men are expected 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 freestyle events can’t be 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 Freestyle 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 1.6 times harder for women to qualify for the 1500 than men.


The 800 Freestyle 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 1.9 times harder for men to qualify in the 800 than women.



Overall, the 1500 cuts are more unfair to women than the 800 cuts are unfair to men.

Proposed Remedy.

Given the long history of sex-asymmetric Olympic distance freestyle, it is not surprising that USA Swimming would bias qualifying times to discourage women in the 1500m freestyle and men in the 800m freestyle.  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 sex asymmetry in its distance freestyle qualifying times.


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


Revision HIstory.

2019-03-15 Published.

2019-12-21 Added qualifying times for 2020 Sectionals, Futures, and Olympic Team Trials.