New details emerge about MLB’s upcoming test of robo-umps in spring training

Major League Baseball is preparing the automated ball-strike system, or ABS, for its biggest test yet this spring training.

MLB has used the so-called robo-umps in the minors, but this will be the first time its used by major-league players.

The upcoming spring experiment will employ the challenge system, in which human umpires will still make the vast majority of calls themselves.

Each team will start a game with two challenges it can issue to an umpire, who will then rely on the automated ball-strike system to review the pitch.

A team keeps its challenge if it is successful.

Advertisement More than 60 percent of spring games will feature the automated strike zone.

The Arizona Diamondbacks are set to use ABS 29 times, the most in the league.

The Chicago Cubs will have the fewest chances at seven.

The average team in the Cactus League will have 21 games featuring the automated zone, with half of its 10 ballparks expected to feature the system.

The average Grapefruit League team will play 19 games with an automated zone, with the system available in eight of 13 parks.

But the system, which includes a slightly different shape of the strike zone and other nuances, is going to take some getting used to.

This week, in a presentation made available to players, the league revealed new details of the system and how it works.

All players in major-league camp have to have their height measured by mid-February so the zone will work properly, and MLB has brought on a third-party company to try to ensure players dont game the system.

Two methods will be used to ensure accurate heights are collected, MLB wrote in the presentation, which was obtained by The Athletic .

A team of independent strength and conditioning personnel will perform manual measurements using standard protocols and equipment.

Representatives of the Southwest Research Institute will use biomechanical analysis to confirm the manual measurements and safeguard against potential manipulation.

One change players will have to adapt to is owed to the fact that robo-umps standardize the size of the strike zone regardless of count.

That differs from the variations customarily shown by human umpires.

According to data the league included in the presentation, at the big league level the human zone on a 3-0 count typically measures 550 square inches.

On an 0-2 count, humans reduced the strike zone to 412 square inches.

By contrast, ABS sets the size of the zone at 443 square inches in every count.

It wasnt clear from what time period the leagues data figures were collected.

MLB declined comment.

Regardless of count, the shape of the strike zone itself will also be different.

Commissioner Rob Manfred has said that the human strike zone tends to look more like an oval, unlike robo-umps whose zones look more rectangular.

A chart included in the presentation displays the difference: As a result, ABS might be more likely to grant pitchers calls on the corner, while it may be friendlier to hitters with pitches slightly below or slightly above the zone.

ABS calls the upper end of the strike zone at 53.5 percent of a players height, and the bottom at 27 percent.

By contrast, humans call the upper edge of the zone at 55.6 percent of a players height on average and at 24.2 percent at the bottom.

Advertisement On their dugout iPads, players will be allowed to review pitch locations and how they likely would have been called by the ABS via an application called ProTabs.

Though the app will have no video, pitches will update after each at-bat.

A challenge adds 17 seconds of game time on average, MLB has found.

In the minors, the league tested a version of the challenge system that allowed teams three challenges per game rather than two.

In three-challenge contests, MLB found that the number of challenges actually issued was 5.8 per game on average.

With two-challenge games, it was 3.9.

The league wants to ensure the action isnt interrupted too often, which is why its trying out the version with only two at the moment.

In the extreme, MLB has seen a game in the minors with 13 challenges (three were available to the teams in that one).

Fan research showed 71 percent of Triple-A fans surveyed viewed a total of four challenges per game or fewer the optimal number.

In the leagues testing of both the two- and three-challenge set-ups in the minors, 62 percent of games achieved that.

If testing goes well, robo-umps could be introduced to regular-season big league games as early as the 2026 season .

The 11-person competition committee controls rule changes.

Because MLB has a majority of votes on the panel, it controls the process, so it could push the matter forward for 2026 if it chooses to.

MLB and the umpires worked out a five-year collective bargaining agreement in December that allowed the league the right to implement ABS, according to a person briefed on the negotiation who was not authorized to speak publicly.

(Top photo of home plate umpire Nelson Fraley wearing an earpiece during a 2022 minor-league game using a version of the automated ball-strike system that will be tested in major league spring training: Imagn file).

This article has been shared from the original article on theathleticuk, here is the link to the original article.