In addition to providing players' times, in seconds, on home-to-first runs, Statcast breaks down these runs in five-foot increments up to 90 feet.
While Sprint Speed incorporates runs of two bases or more on non-homers -- excluding runs from second base when an extra-base hit happens -- and home-to-first runs on "topped" or "weakly hit" balls, a player's 90-foot splits only include the latter.
Because the baseline measurement starts from the back tip of home plate and ends at the back of first base, the home-to-first distance is not exactly 90 feet from a runner's perspective, as home-to-first readings measure the time elapsed from the point of bat-on-ball contact to the moment the batter first touches first base. Moreover, a left-handed batter needs to travel a shorter distance to reach first base than a right-handed batter.
To put every runner on the same 90-foot standard -- in essence a 30-yard dash -- each qualified home-to-first run is extrapolated to 90 feet to generate a player's 90-foot time.
Why it's useful
The ability to filter 90-foot times by five-foot increments provides a more specific look at baserunning speed and allows for more precise comparisons between different players.
Want to see how MLB players' 90-foot baserunning splits compare to nine-time Olympic gold medalist Usain Bolt's splits on his 100-meter dash world record? You can do that too.
Baseball Savant's leaderboard even allows users to select up to four MLB players for a virtual race based on their 90-foot splits.
Watch: Mallex Smith beats out an infield single. In 2018, Smith had the fastest average 90-foot time in the Majors (min. 25 attempts) at 3.73 seconds.