The way they calculate the average sprint speed is good though.
defined as “feet per second in a player’s fastest one-second window” on individual plays. For a player’s seasonal average, the following two types of plays currently qualify for inclusion in Sprint Speed. The best of these runs, approximately two-thirds, are averaged for a player’s seasonal average.
* Runs of two bases or more on non-homers, excluding being a runner on second base when an extra base hit happens
* Home to first on “topped” or “weakly hit” balls.
Basically they only take the plays where players are actually trying to run hard, and average those out.