001.006a Relay Leadoffs are Rare

In USA-S, a time achieved in the leadoff leg of a relay counts as an individual event time.  Many swimmers swim their best in relays, so it is important to capture these times accurately.  Unfortunately, the relay data is imperfect. Some relays are recorded without split times, and many are recorded with demonstrably incorrect split times.  I attempted to recover as many of the relay leadoff splits as possible, but they account for only 2% of the swims in our data.

While relay leadoffs only account for 2% of the swims, 22% of the athletes generated at least one time from a relay leadoff leg annually.

Recognized Leadoff Events.

These statistics are slightly misleading because not all events can be swum as relay leadoffs.  To get a clearer idea of how often athletes swim relay leadoffs, we’ll need to match events that can be swum as both individual events and as the leadoff leg of a relay event.


The following table lists all events that are recognized both as individual events and as the leadoff leg of a recognized relay event.  For example, the 50 backstroke is recognized for 12/Unders as an individual event, and as the leadoff leg of the 200 Medley Relay for all ages.  As a result, we say that the 50 Back (Bk50) is recognized as a leadoff event for 12/Unders, as shown in the rightmost column.


Individual Event

Relay Event

Leadoff Event

Stroke

Distance

Ages

Relay

Distance

Ages

Event

Ages

Freestyle

50

0-18

Freestyle

200

0-18

Fr50

0-18

Freestyle

100

0-18

Freestyle

400

11-18

Fr100

11-18

Freestyle

200

0-18

Freestyle

800

13-18

Fr200

13-18

Backstroke

50

0-12

Medley

200

0-18

Bk50

0-12

Backstroke

100

0-18

Medley

400

11-18

Bk100

11-18


The other tricky event is 200 Freestyle, which is recognized for all ages as an individual event but the matching relay event, the 800 Freestyle Relay, is only recognized for 13/Overs.  As a result, we say the 200 Free (Fr200) is recognized as a leadoff event for 13/Overs.


The following chart shows that 5% of the recognized leadoff events (as identified in the table above) are swum as relay leadoffs.  The remaining 95% are swum as individual events.

Leadoff events are more likely to be swum as relays in the short course than the long course.


Women are slightly more likely to swim SCY relay leadoffs, while men are slightly more likely to swim LCM relay leadoffs.


Shorter distances are more likely to be swum as relay leadoffs than longer distances.  Freestyle and backstroke events of identical distances are swum as relay leadoffs with comparable frequency.


The likelihood of swimming a leadoff event in a relay increases with age within an age group.  This is expected outcome because teams tend to put their fastest athletes in relays, which creates a bias towards athletes at the top of their age group (ages 10, 12, 14, and 18).


The likelihood of swimming a leadoff event in a relay also increases with age, per the quadratic trendline.  This is largely because meets have a fixed number of relays, and older athletes swim fewer individual events.  As a result the proportion of relays to individual events increases with athlete age.

Conclusion.

We’ve learned that relay leadoffs are much rarer than individual events, even when matching leadoff-possible events.  We’ve also learned that, somewhat counter-intuitively, more frequently swum individual events are also more likely to be swum as relay leadoffs.


Our research also highlights the importance of improving the quality of relay lead-off times.  Age group athletes swimming the first leg of a relay are entitled to receive an official time for their leadoff, with the same likelihood and accuracy as they do in individual events.  Providing accurate relay leadoff times will require changes to the manual timing system and to data quality control. LSCs must push back when they receive results with invalid relay splits.  Timers should be required to get a split (and use the plunger) for the relay leadoff as well as the overall relay.


The next post will address the question of whether athletes swim faster in relays.  We’ll find that while some athletes swim faster in relays on average, most don’t.