The first two batters Drew Pomeranz faced in the Boston Red Sox-Tampa Bay Rays game on April 16 walked — Steven Souza on four pitches, Kevin Kiermaier on seven. From Pomeranz’s body language, he was clearly frustrated with home-plate umpire Ted Barrett and felt that many of the called balls should have been strikes. The in-game strike zone suggested that several of those pitches were very close.
Let’s take another look using PITCHf/x data, with the strike zone as it was called in 2016 displayed as a grey line that outlines the region where umpires were equally likely to call a pitch a ball or a strike (the 50% probability zone). Note that Ted Barrett has extremely consistently called a slightly larger than average strike zone since PITCHf/x became available in 2008.
Here’s Souza’s at-bat. All four pitches were called balls. Three of the four were extremely close, with only the second pitch being unambiguously a ball. The first was probably a strike; the third and fourth were just barely outside the line — the average umpire typically does call those balls. So while Pomeranz was justified in thinking that they could reasonably have gone either way, he only got one probably-wrong call in that at-bat:
On to Kiermaier. The first pitch was a curve, perfectly placed exactly on the bottom edge of the strike zone. Barrett called it a ball, and so would have many umpires, but not all. That’s in the 50% zone again; given that Barrett typically calls a slightly large zone, Pomeranz could have reasonably hoped for a strike. The second pitch was also very close to the bottom of the zone, but fairly clearly outside, and it was a ball. The third was clearly a ball. The fourth was just inside the zone, and on his eighth pitch of the game Pomeranz got his first strike. On the fifth pitch, a batter finally took the bat off his shoulder; Kiermaier fouled off the pitch, although it was marginally below the zone and Barrett would have probably given him the ball. The sixth pitch, well inside the strike zone, was also fouled off. Finally, the seventh pitch of the at-bat was several inches above the top of the strike zone, and Kiermaier walked.
So, in the first two at-bats, Pomeranz threw 11 pitches, eight of which were called balls. Only one of those balls (the first pitch to Souza) should clearly have been called a strike. Another few (the third and fourth to Souza, the first to Kiermaier) were almost exactly on the line, and could have gone either way; Pomeranz hit his targets almost perfectly and was justifiably frustrated, but Barrett made reasonable calls.
Looking at the whole game, Barrett’s calls were decent, but not great. In the chart below, called strikes are red, balls are blue. There are two balls each to right- and left-handed batters that should have been strikes, including a couple that (at least according to PITCHf/x, which is not perfect) were fairly egregious. There are also a number of called strikes to righties that should have been balls, including three that are comfortably outside the strike zone, and there are two called strikes to lefties that were further from the bottom of the zone than a ball:
All in all, Barrett wasn’t terrible. He did a better job on the first two batters than it seemed at the time. But he wasn’t great, either, and Pomeranz deserves some credit for excellent pitch location that didn’t get the calls.