Here’s what a ball-strike challenge system in Major League Baseball could look like.
In the above video, Yankees prospect Jasson Domínguez takes a borderline pitch at the knees in the Arizona Fall League on Oct. 7.
It’s called a strike by the home-plate umpire. Domínguez challenges the call, and the automated ball-strike (ABS) system proves him right.
The pitch is shown crossing the plate just below the strike zone — using the same type of 3D visualization of the ball’s trajectory through the zone that you often see on TV broadcasts of MLB games after close pitches — and the call is overturned to a ball. Domínguez walks.
The ABS challenge system was implemented at some levels of the Minor Leagues this season, and the experimental rule is also in place in two ballparks in the Arizona Fall League right now. Rather than use a “full ABS” system to make every ball and strike call (so-called “robot umps”), it gives players on each team the opportunity to challenge the umpire’s call.
On a challenge, the ABS system, powered by the same Hawk-Eye technology used for Statcast in the Major Leagues, determines whether the pitch is a ball or strike. Only the batter, pitcher or catcher can challenge a ball or strike call. Each team gets three challenges per game, with successful challenges retained for future use in that game. In testing to date, the success rate of challenges has been approximately 45 percent.
Domínguez’s challenge came in the seventh inning of a tie game between his Mesa Solar Sox and the Salt River Rafters, with a runner on first base, no outs and a 3-1 count. That’s the type of key situation in which you might expect to see the ABS challenge system used, with the limited number of challenges teams are afforded per game.