Apparently, young umps are better than old umps and robots are better than both.

I’d love for MarkR and everyone else to keep track of the good, bad and ugly, because I don’t keep track of them unless they’re historically bad (the usual suspects)

AAx is short for Accuracy Above Expected, which weights an umpire’s calls based on league tendencies.

I sincerely doubt that the MLB is going to go to an all robot umpire model any time soon.

What I’ve seen proposed and mentioned a bunch of times is the ability to challenge a ball/strike call similar to the challenge system now, but with it just being a computer measured strikezone. There is a lot of positive feedback from the leagues that have used that system so far.

As for young umps vs. old umps and their strike zones, the trend is definitely leaning heavily that the young umpires are better, but I don’t think there is much surprising about that.

The feedback system used to be that it didn’t matter if you were right as long as you were loudly defending your call.

Umpires get a composite breakdown of their balls and strikes after each game and a score similar to the Umpire Scorecards, but with a little softer total zone (they give them a little leeway on each edge of the zone).

There was a really cool NYT Magazine article about umpires the other day I read. Some of it it a little silly, but there is some interesting info in it as well:


This is basically the “tennis” model, where they still have line judges and a chair umpire for routine plays, but the players get a certain number of challenges of in/out calls for ones that seem close. It seemed weird at first, but it’s worked pretty well for like a decade and a half, and now it’s just routine. And there’s a fun moment of suspense when they play an animation in the stadium showing the ball hitting the court and zooming in on how close the ball came to the line. Sometimes the audience cheers or laughs when it’s a particularly close call.

I’d definitely prefer that approach to, for example, Scott Servais delaying the game to throw a tantrum because Laz Diaz is having a bad night.


I believe that’s called “Tuesday”.

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