Introduced during the 2017 season, Sprint Speed is a Statcast metric that aims to more precisely quantify speed by measuring how many feet per second a player runs in his fastest one-second window.
Note: Though Sprint Speed will be applied across a variety of running and speed-based situations at some point in 2017, for now it is available only for outfield defense.
Why it's useful
The metric provides a much truer sense of a runner's ability than Maximum Speed, another Statcast metric. Approximately seven full-effort strides can be captured over the course of a one-second window, so Sprint Speed rewards those who can sustain their speed over a longer period of time. Max Speed doesn't necessarily take that into account, as it measures a player's top speed at any point in a particular run -- even if that speed was reached for only a fraction of a second.
On an individual outfield play, Sprint Speed is the basis of Statcast's speed-based range metric, Catch Probability. On a cumulative basis, the metric can be used to create a variety of speed-based leaderboards.
Example: The following leaderboard resulted from averaging the top 5 percent of speed times on outs for each of the 118 outfielders with at least 100 fielding opportunities in 2016. The top 5 percent filter was used to eliminate the many easy jogs each outfielder has throughout the season.
Top 2016 Sprint Speed by outfielders
29.8 feet per second -- Billy Hamilton
29.7 feet per second -- Byron Buxton
29.1 feet per second -- Lorenzo Cain
29.0 feet per second -- Paulo Orlando
28.7 feet per second -- Jake Marisnick
28.6 feet per second -- Gregory Polanco/Travis Jankowski/Max Kepler
28.3 feet per second -- Christian Yelich
28.2 feet per second -- Kevin Kiermaier
Watch: Statcast measures Lorenzo Cain's Sprint Speed at 28.5 feet per second on a running catch.