001.006b Some Athletes Swim Faster in Relays

Two of the four possible national age group records in the 50 yd Backstroke were set in the leadoff leg of a 200 yd medley relay.


Age Group

Gender

Year

Name

LSC

Time

Relay

10/Under

Female

2015

Miriam Sheehan

AZ

27.27

N

10/Under

Male

2015

Ronald Dalmacio

CA

26.91

Y

11-12

Female

2014

Regan Smith

MN

25.69

Y

11-12

Male

2017

Ronald Dalmacio

CA

23.65

N


This is statistically remarkable because only 4.6% of the 12/Under 50 yd backstroke times were generated in relay leadoffs rather than in individual swims.  Thus the likelihood of setting a 50 yd backstroke record is 20 times higher as relay leadoff than as an individual swim! In this post, we'll consider whether athletes swim faster in relays.  My own experience is that some do, and some don’t. Let’s see what the data says.


To answer this question, we’ll limit our analysis to all athletes of a given age who have swum a recognized leadoff event at least once as both a relay leadoff and an individual event.  Then we’ll report the likelihood that a time achieved in a relay leadoff by a given athlete in a given year is faster than a time achieved in the corresponding individual event by that same athlete.  For example, let’s say that our athlete swam the 50 back in 30 and 32 seconds as relay leadoff and 31 and 33 seconds as an individual event. Then the athlete’s relay leadoff times beat their individual times three times out of four, with a likelihood of ¾.  This metric is greater than ½ when leadoff times are faster than individual times, and less than ½ when leadoff times are slower than individual times.

Ronald Dalmacio’s 50 yard Backstroke Records.

Let’s work through a concrete example.  In 2015, Ronald Dalmacio set a national age group record in the 10/Under 50 yard backstroke.  As a 10 year old, he swam the 50 yard backstroke sixteen times, eight times each as an individual event and relay leadoff.  His fastest time was a 26.91 as a relay leadoff, which he achieved on May 1, 2015 (shown with a red star).


The graph shows that his individuals were faster than his leadoffs early in the season, while his relay leadoffs became faster than his individuals later in the season.  Overall, his relay leadoffs were faster than his individuals 59% of the time during his 10th year. We’ll note, however, that the most significant trend in this graph is the age-related decline in time.


Here are all of Ronald’s 12/Under Bk50Y times.  He set national age group records in this event at age 10 as a relay leadoff (red star) and again at age 12 as an individual event (blue star).


Each cluster is a short course season, starting with age 8.  The graph shows that for most ages, Ronald swam the 50 Back faster as an individual event than as a relay leadoff.  We can summarize this information in two charts.


The first chart shows how many times Ronald swam the Bk50Y in each year.


The second chart shows that in only one year (age 10) did Ronald swim the relay leadoffs faster than the individual events. At age 9, all of his individuals were faster than his relay leadoffs.

Athletes Don’t Swim Faster in Relays.

Overall, age group athletes swim leadoff events faster in relays than individually 49.89% of the time, which means that, on average, age group athletes don’t swim faster in relays.




However when we drill down into the data, we’ll learn that some athletes swim faster in relays.

Older Athletes Swim Faster in Relays.

13/Over athletes are likely to swim leadoff events faster in relays, while 12/Unders are more likely to swim leadoff events faster individually.

Athletes Swim Faster in LCM Relays.

Athletes are more likely to swim leadoff events faster in LCM relays than they are in SCY relays.



This LCM/SCY disparity is independent of the age-related decline in SCY participation.

Men Swim Faster in Relays.

Overall, men are slightly more likely to swim faster in a relay leadoff, while women are slightly more likely to swim faster in an individual event.


We’ve already seen that 13/Over athletes are more likely to swim faster in relays than 12/Under athletes.  This plot shows that men have a greater likelihood of swimming faster in relays than women in all age groups.

Longer Events are Faster in Relays.

Athletes are more likely to swim longer leadoff events faster in relays, for both freestyle and backstroke.  The two best leadoff events to swim in a relay are the 400 and 800 free relays. It’s ironic that the rarest leadoff events are the ones most likely to have faster relay leadoff times.


This is at least partially an age-related effect, because we’ve seen that older athletes, who are more likely to swim faster in relays, are also more likely to swim longer events.  However the following plot shows that even after we control for age, longer less frequently swum events are more likely to be swim faster in relays than shorter more frequently swum events.


Individualists Swim Slower in Relays.

The more frequently an athlete swims a leadoff event individually, the less likely they are to swim that event faster in relays.


Athletes Who Swim Faster in Relays Swim More Relays.

Finally, let’s consider the converse question: who is more likely to to swim leadoff events in relays?  The following plot shows that athletes who swim leadoff events faster in relays are more likely to swim those events in relays than individually.  And, conversely, athletes who swim leadoff events slower in relays are increasingly likely to be excluded from relays.

Conclusion.

We’ve learned that on average, age group athletes are equally likely to swim leadoff events faster in relays and individually.  However, there are exceptions to this rule where certain athletes are more likely to swim faster in relays, such as older athletes, male athletes, athletes who swim an individual event infrequently, and athletes swimming longer distances or in long course events.


We’ve also noticed a strong correlation between the infrequency of a leadoff event and the likelihood of an athlete swimming that event faster in the relay than individually.  Men’s swims are less frequent than women’s; men are more likely to swim leadoff events faster in relays. Older athletes compete less frequently than younger athletes; older athletes are more likely to swim leadoff events faster in relays.  LCM swims are less frequent than SCY swims; athletes are more likely to swim leadoff events faster in LCM relays than in SCY relays. Longer events are swum less frequently than shorter events; athletes are more likely to swim longer leadoff events faster in relays.