Nobody From Nowhere (@i8dc)

Occasional Common Sense

How Much Does It Matter When An Umpire Calls A Pitch Wrong?

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With two outs in the 8th inning of the Reds’ 1-0 victory against the Nationals yesterday, Reds closer Aroldis Chapman was brought in to face Adam LaRoche with runners on first and second.

The matchup was good for the Reds; the flame-throwing lefty Chapman has a FIP (fielding-independent pitching) of 0.59 — far better than any other pitcher in baseball this year, and is particularly brutal on left-handed hitters, holding them to an OPS (on-base plus slugging) of just .344 this year. LaRoche was 0-2 against Chapman in his career, and has an OPS against lefties this year of .647, vs. .894 against righties.

Chapman missed with his first two two fastballs, at 101 and 99.5 mph. With his third, he throttled back a little more and got a called strike on the outside corner. But this pitch was clearly a ball, and was indeed the worst pitch call umpire Jeff Nelson made on this day.

chapman-laroche bs2

chapman-laroche bs3

PITCHf/x data from

PITCHf/x data from

So the ump blew the call. So what? Well, the difference in situations and odds is significant.

Over his career, with a 2-1 count, batters have gone on to reach base safely against Chapman 39% of the time; with a 3-0 count, this number leaps to 72%.  Over LaRoche’s career, with a 2-1 count his on-base average is .405 with an OPS of .861; with a 3-0 count LaRoche gets on base 74% of the time and his OPS jumps to 1.338.

If Nelson had correctly called the pitch a ball, LaRoche’s odds of getting on base would have been more than 80% higher. 

Note, I’m not saying that the Nats would have come back against Chapman if this pitch had been called correctly, because he has been off-the-charts sick this year.

But I am saying that it’s an unfortunate and unnecessary problem that umpires are so often wrong calling the edges of the strikezone. There’s really no reason to not automate this function in Major League Baseball.


Written by David Clayton

July 27, 2014 at 8:45 am

Posted in Debunkery

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