Eric Cooper’s Strikezone
The Astros and Yankees are set to meet tonight in the first postseason game of 2015, with the winner advancing to play the Royals in the division series. While both teams are likely to do everything they can to win tonight’s game, there is one potentially significant variable they won’t be able to control; the called strike zone. So that’s preview what we might look for from the home plate umpire tonight.
17 year veteran Eric Cooper is going to be behind the plate for the Wild Card game. Per Baseball Heat Maps, here’s Cooper’s called strike zone compared to the league average (warmer colors indicate more calls in that area).
RH hitters
LH hitters.
The first thing that stands out is that Cooper has a very tall strike zone, calling far more pitches than the average umpire at both the top and bottom of the rulebook zone. He’s especially generous at the very top sliver of the zone with a right-handed batter at the plate, which is also a very tough area for hitters to make contact on. He offsets the height of his zone to some degree by having a fairly narrow strike zone compared to the average umpire, calling fewer pitches away against both lefties and righties, but the effect isn’t as large as his large vertical zone.
As you can see at the charts available over at Baseball Savant, Cooper calls an above average pitches out of the zone as strikes, and has one of the lowest rates of calling pitches in the zone balls. Overall, he’s a pitcher friendly umpire, and hitters are going to need to protect the plate more often than they normally would, especially on high and low pitches.
Interestingly, neither Keuchel nor Tanaka attack the top of the strike zone that regularly, as both are primarily trying to keep the ball down, so there’s not a clear advantage to either side based on the umpire tendency with regards to the starting pitcher. But both teams are likely to use an army of relievers, and Cooper’s zone could work out pretty well for a pitcher like Houston’s Josh Fields, who likes to pitch up with his fastball.
Dave is the Managing Editor of FanGraphs.


Good. Surprised the Nerds haven’t developed sheets of stats on umpires giving overwhelming influence an extremely large or small zone can have on a game. Brooks used to keep tabs on the umps, figured that would be good for fg.
So should pitcher friendliness from home plate umpires be calculated into pitcher WAR? It’s just an extension of trying to subract defense.
Ump effects and framing seem to me to be the same sort of “signal” in that both influence the called zone, and currently neither impacts pitcher WAR.
Of the two, for most pitchers, I’d have to say catcher framing is probably the more significant factor, because a pitcher deals with a given framer for 50+% of his innings (and most of the rest by a single other framer), while a pitcher might reasonably pitch to dozens of umps, for one game each.
Baseball Prospectus’ DRA (and the derived WAR variant, PWARP) takes umpire and catcher effects into account for its calculations. Very interesting stat to say the least.
But, does he play Draft Kings?
Seems to just have an anti-Yankee zone tonight. Has missed several pitches against Tanaka and several for Keuchel.
Statistically, he was the most pro-Keuchel ump in all of MLB this season. Assigning him to this game was a willful ploy by MLB.
Horrible umpiring. Mlb rigged it. Cooper is a kc fan also.
It was an embarrassing display of umpiring but I think he’s just bad at his job. I doubt MLB would rig a game to knock the largest market out of the playoffs.