Let’s go ahead and get this out of our systems: Wednesday night, some Cardinals got ejected for complaining in a game the team won. Some people might call that the very most Cardinals thing. Those same people are just people who don’t like the Cardinals, but, whatever, everyone’s entitled to his or her own feelings, and we should get this out of the way before proceeding. All right, it’s out of the way! So let’s unpack a picture:

What you see is a play in progress. It’s a bases-clearing double, that put the Cubs ahead. As the Cubs were in the process of rounding the bases, and as the Cardinals were in the process of retrieving the baseball from the outfield, Yadier Molina argued with home-plate umpire Pat Hoberg. We see Molina with his back turned to the plate, even though there might soon be a play right there. (There wasn’t.) Arguments are common; arguments during plays are less common. Molina was shortly ejected. The same went for his manager. The game had been leading up to this moment.

It’s time to hit the rewind button. A picture from moments earlier, in the same at-bat:

That’s Molina, in Hoberg’s face. Molina didn’t like a call in a 2-and-2 count. The call, and the pitch:

Not a lot wrong, there, from the Cardinals’ perspective — Molina set a target, and Michael Wacha hit it. The target was just barely off the plate, almost imperceptibly. It seemed like the pitch was perfectly located in the low-away corner, and with a called strike, that would’ve meant the end of the inning, with the lead preserved. Because of the ball, the count ran full, which meant all the runners would be going, which meant the Cubs benefited greatly. Two pitches later, there was the double. Here’s a screenshot of the pitch right around when it was crossing the plate:

I don’t know how much that helps, especially with the off-center angle, but it’s good to have it frozen. Obviously, the pitch was around Miguel Montero’s knee level. Obviously, the pitch was around the outer edge of the plate. Obviously, the pitch could’ve been called a strike. Obviously, a strike call wasn’t going to be automatic.

It wasn’t all about one pitch or one at-bat, though. From Jenifer Langosch:

Both Molina and starting pitcher Michael Wacha said it only took three pitches to realize they might be dealing with a tight strike zone from Hoberg, a Triple-A umpire who began working occasional games in the Majors last season.

Some ball calls from the Cubs’ first plate appearance:

And then there’s carryover frustration from the previous night — on a critical play, Pat Hoberg ruled this ball was fair. The Cardinals disagreed, but the play was unreviewable. So Hoberg was already a target, before he started calling balls and strikes Wednesday. There was, as one might say, a preexisting beef.

For an idea of what the Cardinals were dealing with, we can make use of Brooks Baseball. There we can find strike-zone plots, and here’s Hoberg’s zone for right-handed hitters:

Perhaps more importantly, here’s Hoberg’s zone for left-handed hitters:

The darker rectangle approximates the rule-book strike zone. The bigger rectangle approximates the strike zone as it’s actually called, on average. With lefties, you see a tight zone, with a number of pitches within one rectangle but not the other. All those pitches were called balls. As Molina picked up on, Hoberg was calling a particularly tight game. Too tight, in Molina’s mind, and he eventually expressed his frustration. From post-game:

“Michael was pitching well. That’s the sad part,” said Molina. “[The strike zone] was like that all night. He’s a young umpire, and he needs to figure out a better strike zone. That’s it.”

About that: Baseball Savant offers some limited evidence. Here are umpire plots for 2015, with a red arrow designating Hoberg’s place within the population. Rate of strikes on pitches out of the zone:

Meanwhile, rate of balls on pitches in the zone:

Nothing too bad. Hoberg, to this point, hasn’t been extremely hitter-friendly or extremely pitcher-friendly. He’s been fine, in his games, but then the whole record of Hoberg’s games is less important today than just Hoberg’s Wednesday game, the game with which Molina took issue. It doesn’t matter what he’s done overall; it just matters what he did with Molina and Wacha. And you have to consider the game Molina caught the night before. The Angel Hernandez strike-zone plot for righties:

And the Hernandez strike-zone plot for lefties:

Hernandez, Tuesday, called a fairly big zone. Molina caught that zone, and it was a more familiar sort of zone than Hoberg’s. It would’ve been only natural to assume the same calls would happen on Wednesday as on Tuesday, but then Molina found out early that wouldn’t be the case. He said he talked to Hoberg over the course of things, to try to get a bigger zone. Look at the way Molina set up with Dexter Fowler in the first:

And now look at how Molina set up with Montero in the sixth:

In the first, Molina was more square to the pitcher. In the sixth, he was at more of an angle, perhaps to try to give Hoberg a better look. That could, alternatively, just be because there were runners on base in the sixth, but it could still have been a strategy to try to get more favorable calls. Of note, the above shot is from the controversial 2-and-2 pitch. Here’s a shot from the next pitch:

Molina set up the same. He didn’t do anything meaningfully different. He must’ve known, beyond a shadow of a doubt, the zone was small. He still called and looked for that pitch in the corner. On the one hand, you don’t want to change your strategy because of the umpire. On the other, it’s not like Molina didn’t know what was going on. He kept trying to get that edge.

And it’s an edge he usually gets. This is important. Those pitches just off the plate, to lefties: they’re usually strikes. Overall, they’re strikes more than three-quarters of the time. That applies overall, that applies to when Molina is catching, and in a small sample, that’s applied to when Hoberg has been the umpire. Hoberg hasn’t always shut that edge down. Some of the close calls took place in two-strike counts, and Molina probably understands that with two strikes, the zone gets a little smaller. But even there, maybe they’re coin flips. Hoberg just kept calling ball, over and over.

When you lay it all out, each side is entirely understandable. No, let me walk that back — it’s never understandable to have a player arguing in the middle of a play. But you get Hoberg’s position, and you get Molina’s. For Molina, he knew that was a smaller zone than usual. He knew he’d just had a bigger zone the night before. He knew there wasn’t anything wrong with his catching, or with Wacha’s pitching. Pitches that would often be strikes were getting called balls. For Hoberg, his defense is the rule book. The pitches being complained about were almost exclusively off the plate. Pitches off the plate aren’t supposed to be strikes. Pitches off the plate commonly are strikes, but a revolution starts with one man. Hoberg, technically, wasn’t in the wrong. Why should Molina feel so entitled to a more favorable zone, when he knows he’s trying to stretch off the plate? Why should that be the norm?

I don’t know what was said that provoked the ejection. I don’t know if Molina crossed the line, or if Hoberg over-stepped. Players frequently go too far, but the same goes for umpires, especially umpires low on self-confidence. But this is more about what led to the confrontation, not the confrontation’s result. What we had was an umpire calling a strike zone that looked more or less like something out of the rule book. But because the rule-book strike zone isn’t the zone that gets called, in reality, the Cardinals were pissed. It made sense for the Cardinals to be upset; it made sense for Hoberg to defend himself. No one is all the way right, and no one is all the way wrong. It’s a situation all about gray areas. The game, probably, would be better with a smaller strike zone. But as long as such zones are selectively or randomly enforced, there’s going to be conflict. Catchers and pitchers have grown increasingly comfortable, and they’re not going to want to give up what they’ve gained.