Analyzing the Umpires: World Series Edition

Yesterday, the names of the World Series umpires were released, with John Hirshbeck serving as the crew chief. Like I have done for the first two rounds in the playoffs, I will examine each umpire’s strike and ball calling tendencies. Overall, the group is pretty solid, with the exception of Bill Miller, who calls one of the league’s largest strike zones.

For each umpire, I have include their 3-year average K%, BB% and Zone% for both left-handed and right-handed hitters. To get the Zone%, I looked at the number of called strikes and balls in the league average called strike zone. The strike zone used is the same one that is used for FanGraphs hitter and pitcher Pitchf/x Zone% values.

Also, I have created a 100 scale which shows how much more or less an umpire’s values are compared to the league average. A value over 100 is always pitcher friendly (a lower BB% means a higher value).

Additionally, I have included a heat map of the umpire’s called strike zone compared to the league average zone. It subtracts the percentage of called strikes divided by the total of the called balls and strikes of the umpire from the league average. For example, if the umpire called a pitch in the zone a strike 40% of the time and if the league average is 50%, the output would be -10% (40%-50%) or 0.10.

John Hirschbeck – He calls an average number of balls and strikes. His zone is shifted down and inside.

LHH: 3-year
K%: 23.1% (95)
BB%: 11.3% (103)
Zone%: 52.9% (105)

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RHH: 3-year
K%: 26.4% (108)
BB%: 10.6% (99)
Zone%: 79.6% (99)

LHH

RHH

Dana DeMuth – He squeezes the zone a bit on the sides, but then calls strikes more at the zone’s top and bottom. He is friendly to LHH compared the the league average umpire.

LHH: 3-year
K%: 22.9% (94)
BB%: 12.9% (91)
Zone%: 48.9% (97)

RHH: 3-year
K%: 23.9% (98)
BB%: 10.5% (99)
Zone%: 79.1% (98)

LHH

RHH

Paul Emmel – He is overall neutral with his LHH zone squeezed in a bit.

LHH: 3-year
K%: 23.8% (98)
BB%: 12.0% (97)
Zone%: 50.5% (100)

RHH: 3-year
K%: 24.2% (99)
BB%: 11.9% (88)
Zone%: 79.7% (99)

LHH

RHH

Jim Joyce – Overall, Joyce is neutral. He shifts his zone down a bit. For right-handed hitters (RHH), he doesn’t call the high strike.

LHH: 3-year
K%: 23.6% (97)
BB%: 11.5% (102)
Zone%: 49.8% (99)

RHH: 3-year
K%: 24.3% (99)
BB%: 10.5% (99)
Zone%: 80.5% (100)

LHH

RHH

Bill Miller – He calls one of the largest strike zones in the league.

LHH: 3-year
K%: 25.6% (105)
BB%: 9.8% (120)
Zone%: 51.6% (102)

RHH: 3-year
K%: 25.7% (105)
BB%: 9.7% (107)
Zone%: 84.3% (105)

LHH

RHH

Mark Wegner – He squeezes the zone in on the edges and then extends it to the top and bottom.

LHH: 3-year
K%: 26.6% (109)
BB%: 11.5 (102)
Zone%: 50.6% (100)

RHH: 3-year
K%: 23.4% (95)
BB%: 10.6% (98)
Zone%: 82.0% (102)

LHH

RHH





Jeff, one of the authors of the fantasy baseball guide,The Process, writes for RotoGraphs, The Hardball Times, Rotowire, Baseball America, and BaseballHQ. He has been nominated for two SABR Analytics Research Award for Contemporary Analysis and won it in 2013 in tandem with Bill Petti. He has won four FSWA Awards including on for his Mining the News series. He's won Tout Wars three times, LABR twice, and got his first NFBC Main Event win in 2021. Follow him on Twitter @jeffwzimmerman.

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Bad Bill
12 years ago

These are very interesting reports, but one thing that would have made them more interesting is a “consistency” rating. Players seem to adapt reasonably well to short, squat strike zones or low, outside strike zones as long as they are called consistently. It’s the ones where two pitches in the same location produce different calls that drive players, and maybe even more so fans, up the wall. Is there any way to evaluate consistency from the data you have? ‘Twould be appreciated.