YORK, Pa. — “Robot umpires” have arrived.

The independent Atlantic League became the first American professional baseball league to let a computer call balls and strikes at its All-Star Game. Plate umpire Brian deBrauwere wore an earpiece connected to an iPhone in his pocket and relayed the call upon receiving it from a TrackMan computer system that uses Doppler radar.

He crouched in his normal position behind the catcher and signaled balls and strikes.

It didn’t appear deBrauwere had any delay receiving the calls at first but players noticed a delay at times. Infielder L.J. Mazzilli said a few times hitters who struck out lingered an extra second or so in the batter’s box waiting on a called third strike.

The umpires have the ability to override the computer, which considers a pitch a strike when the ball bounces and then crosses the zone. TrackMan also does not evaluate check swings.

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