Tuesday, May 8, 2007


Is it a marathon or a sprint? Whether it is the advice her mentor gave profgrrrl about research and publication after - as well as before - getting tenure, the results of the Kentucky Derby this weekend, or planning/updating the way a college course is presented, the same question arises. Can a steady pace win the race?

Today I am writing about the strong finish by Street Sense in the derby, and how it resulted from good pacing. (I am also thinking about new examples I can use this week and in the fall, involving average velocity in a "come from behind" victory.) Lets compare the split times for the two horses at the quarter mile points in the race. (Apology for the crude table.)

  • time in s (split) - Hard Spun - Street Sense
  •   22.96 (22.96)   -   23.0   -   25.6 *
  •   46.26 (23.30)   -   23.3   -   23.6 *
  •   71.13 (24.87)   -   24.9   -   23.8 *
  •   97.04 (25.91)   -   25.9   -   24.5 *
  • 122.17 (25.13)   -   25.5 * -   24.6 *
The * indicate an estimate (quite crude in some cases) of the split time based on the published gaps between horses and about 0.15 s per length. [*] For example, Hard Spun finished second, 2 1/4 lengths behind, suggesting a time of 25.5 s for the final quarter mile, finishing about 0.34 s after Street Sense. Street Sense was 3 1/2 lengths behind at 1 mile, so he probably ran the final quarter in 24.6 after making up about 0.53 s at the mile pole.

For reference, Street Sense's winning time corresponds to an average of 24.43 s per quarter mile (which is 36.8 mph). He ran the last quarter at close to his average speed for the entire race. He pulled away because the other horses slowed down, not because he was speeding up.

Profgrrrrl might notice the similarity between the way the winning horse ran this race and the philosophy behind the training program she is using to get ready for the San Diego marathon. A repeated emphasis is on training at "race pace", so you can learn to avoid the fast-start no-finish syndrome of road racing. Now back to thinking about the pacing for my class that starts this week, and how to get the students to run it as a marathon ... doing some homework every day. The example above might help with that.

The length of a thoroughbred horse is not easy to find via Google. Estimates were based on 8.25 ft length (the length of a full size statue of a horse being sold on the web), divided by 54 ft/s. That adds 0.152 seconds for each length. Another estimate on the web equates a length with 0.2 seconds for handicapping purposes, but that is not for top 3 year olds. In any case, the largest error is due to the accumulated round-off errors made when I added up the gaps that someone estimated for the distance between the horses at each point on the track. I'm impressed with how consistent these estimates seem to be. Must be the usual effect of random errors tending to cancel out.

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