Major League Baseball can envision a day when mechanical umpires could be tested to call balls and strikes.
Baseball has used computer systems since 2001 to evaluate ball-strike calls, and umpires responded by gradually realigning their strike zones back toward the rule-book definition.
Commissioner Rob Manfred was asked on Wednesday before the NL wild-card game whether baseball may eventually use a mechanical strike zone.
"The technology of calling balls and strikes without a human being involved has continued to improve,'' he said.
"The principal reason that we've always done it after the fact is unlike the box that you see on a broadcast, our system that we use to grade our umpires, someone goes in and manually adjusts the strike zone for the batter.
"And there are material differences in the strike zone.''
Baseball has used expanded video review since 2014, but balls and strikes are not subject to review.
In 2015, an independent league tested Sportvision's the PITCHf/x automated system to call balls and strikes.
"As technology continues to improve and those sorts of adjustments can be made real time, that technology will become more feasible for use on the field,'' Manfred said.
