001.011 Finals are Unfair

A previous post noted that 39% of preliminaries swims qualify for finals.  In other words, on average there is one finals slot for every 2.5 preliminaries slots.  This post analyzes how participation in preliminaries and finals varies with age, gender, and performance.  We’ll see that it’s easier for men to make finals than women, and that athletes at the top of their age group are more likely to make finals than the other athletes in their age group.

Likelihood of Entering Preliminaries.

Let’s start with the preliminaries.  This graph plots the fraction of preliminaries swims versus non-finals swims of a given age and gender, across both seasons.  It shows that older athletes are increasingly likely to participate in preliminaries and finals, with minor gender differences.

The wiggles, which are more noticeable on the men’s plot, are a weak age group effect. Recall that USA-S sanctions four age groups: 10/Under, 11-12, 13-14, and 15/Over.  Our plot shows that the athletes at the bottom of their age groups (aged 6-9, 11, 13, and 15) participate less in preliminaries than the athletes at the top of their age groups (aged 10, 12, 14, and 18) .  This is because roughly 50% of preliminaries have qualifying times, which disadvantage the younger swimmers in each age group. The effect is reduced for the oldest age group because the performance differences inside that age group are smallest.  The effect is enhanced for men because age-related performance differences are greatest for men.


To recap: while more women than men participate in age group swimming, their relative participation in preliminaries is similar.

Older Athletes within Age Groups are More Likely to Make Finals.

Let’s now turn to finals. This graph plots the likelihood of a swim making finals, as a function of age. The most noticeable feature of this plot are the three giant wiggles.


The wiggles in this plot are a strong effect of USA-S age groups. Swimming performance increases rapidly from ages 6 to 14, and more slowly from ages 15 to 18.  As a result the athletes at the top of their age group (ages 10, 12, 14, and 18) tend to be faster than the younger athletes in their age group, and hence are more likely to make finals.


This plot shows that athletes at the top of their age group are 1.2 to 1.5 times more likely to qualify for finals than those at the bottom of their age group.  The effect is strongest in the 9-10 age group and weakest in the 15-18 age group.


Improving Athletes Are More Likely to Make Finals.

Athletes who beat their seed time in the preliminaries (“Drop Time”) are 1.3 times more likely to make finals than athletes who do not beat their seed time in the preliminaries (“Add Time”).

The advantage of dropping time in the preliminaries holds across all ages.  An 11-year-old athlete who drops time in the preliminary has roughly the same chance of making finals as a 12-year-old who does not. It’s a significant advantage.

It’s Easier for Men to Make Finals.

Overall, it’s 1.15 times easier for men to make finals than women.


With one exception, it’s easier for men of all ages to make finals than women.  This raises two questions: why are men more likely to make finals overall, and what’s different about age 15?

We’ll ignore 9/Under swims for the purposes of this discussion because there are few finals swims in that age range.  From ages 10 to 14, men are 1.15x to 1.35x more likely to make finals than women. The reason is simple. From ages 10 to 14, women are responsible for 1.3 - 1.6 times as many preliminaries swims as men.  Finals have the same fixed number of slots (either 1, 2 or 3 heats) for both men and women, which means that men have a 1.3 to 1.6x greater opportunity to make finals than women. The actual likelihood ratio is determined by the number of athletes who enter a given event.  So if the same number of men and women enter a given event, then men and women will have the same likelihood of making finals in that event. And when an event has fewer participants than finals slots, all participants swim in finals. But the overall picture is clear: having the same fixed number of finals slots for each gender means it will on average be much easier for 16/Under men to make finals than 16/under women. In a later post, we’ll learn age group championship meets have qualifying times that systematically exclude women from participating in preliminaries.


Why are 15 year old women more likely to make finals than 15 year old men?  The answer to this quirk lies in the interaction between athlete development and the USA-S age group system.  From age 15 to age 18, men’s performance improves more rapidly than women’s performance. As a result, it is much less likely that a 15 year old man will out-swim an 16/Over man on average than it is for a 15 year old woman to out-swim a 16/Over woman.

Indications of a Relative Age Effect.

Consider the wiggles in the graphs above.  In a previous post, “Athletes Swim Faster in Finals” (link), we saw that the “dropping time” metric varies by age rather than age group.  Athletes aged 8 to 12 were similarly likely to drop time in preliminaries, while athletes aged 13 to 18 were less likely to drop time. Conversely, the “making finals” metric varies by the athlete’s relative age within their age group.  As a result, athletes at the top of their age group (ages 10, 12, 14, and 18) receive disproportionate recognition for their accomplishments than those at the bottom of their age groups (ages 6-9,11,13,15-17). The disparity is particularly severe in the 10/Under and 11-12 age groups, where athletes are improving at comparable rates but the 10- and 12-year-olds are more than 1.5 and 1.4 times more likely to be rewarded for their efforts than the 9- and 11-year-olds, respectively.


Per sports science research, this disparity between performance and recognition is a relative age effect.  A relative age effect occurs when developing athletes are grouped together by age and then rewarded for their performance relative to their age group.  This results in a profoundly unfair system that favors the eldest athletes in the group (ie., those at the top of their age group), who are led to believe their athletic performance is better than it really is, and harms the youngest athletes in the group, who are led to believe their athletic performance is worse that it really is.  We will return to this important issue (link), where we’ll show that the relative age effects in age group swimming harm those athletes whose birthdays fall before end-of-season championships.


To be clear, I’m not claiming that the existence of age groups by itself causes a relative age effect. Rather, I’m claiming that the disparity between improvement and recognition within an age group, as demonstrated by the data above, is a relative age effect, and that more research is required to understand its scope and potential harms.

Indications of a Gender Bias.

Age group athletes measure their success in part by the number of championship meets they attend, the number of championship events they qualify for, and the number of finals they make. Athletes who make finals may have their names announced in the preliminaries session and again in the finals session. They may even be introduced individually, with music playing, just like the Olympics.  It can be a big deal. Under the current system, it’s intrinsically easier for men to make finals than women, which discriminates against women by disproportionately denying them comparable recognition for their equivalent athletic accomplishments.


Implementing gender equality for USA-S competition format would be easy; simply make the number of finals slots proportional to the number of preliminaries entries. Then an event with twice the number of preliminaries participants would have twice the number of finals contestants, which would automatically eliminate this gender bias.

Conclusion.

We’ve seen that men and women participate in preliminaries at similar rates, but it’s easier for men to make finals. The net effect is that men receive disproportionately large recognition for their accomplishments in age group swimming.  We’ve also seen strong indications of a relative age effect in age group swimming, where older athletes in an age group receive disproportionately large recognition for their athletic accomplishments. In later posts, we’ll investigate the size and scope of the relative age effect in age group swimming.