I want to assure you right away that what follows isn’t sour grapes. I don’t have a dog in this fight. Even if I did, I’d complain on my own time, and not on the job in front of everyone (probably). What follows is about a call, and a controversial one at that, early in Monday’s Game. But I’m not here to talk about various implications. I’m here to talk about the call’s significance, relative to others, and about the process that contributed to the call. It was, in the end, a call most extraordinary that went Boston’s way.

The Red Sox went ahead 1-0 in the first, as you recall. The score remained the same into the bottom of the third, when David Freese led off with a single. Pete Kozma bunted Freese to second, and Adam Wainwright advanced Freese to nowhere with a strikeout. Matt Carpenter came up with two down, and he worked the count full. In that full count, Jon Lester threw a cutter inside. Carpenter started to first, assuming he’d drawn a two-out walk. Bill Miller, however, called him out, and Carpenter expressed his disagreement. That went about as well as most fairly cordial expressions of disagreement on a baseball field. That is, nothing changed, and the game moved on to the top of the fourth, with Carpenter having struck out looking.

From a straightaway angle, here’s the pitch that Carpenter took, right around when it crossed the front plane of the plate:

There’s really no controversy here, at least in terms of what should’ve happened. The pitch was over the edge — not of home plate — but of the batter’s box. That means the ball was inches out of the zone. Vertically, the pitch was fine. Laterally, the pitch missed. It doesn’t even fit in a gray area. That pitch unquestionably should’ve been ball four, and Carpenter should’ve advanced to first, which would have brought up Shane Robinson with two down and two on. Miller just got it wrong. OK.

But it isn’t just that the call was wrong. I wouldn’t be writing on FanGraphs about some ordinary wrong ball/strike call. Below is a plot of all called strikes thrown to lefties by lefties in 2013. Both Carpenter and Lester are left-handed, as I didn’t need to write, and every pitcher/batter combination gets its own strike zone for whatever reasons. Anyway:

You can already guess what the big red dot is. That’s the call that went in Lester’s favor on Monday. Among all pitches thrown by lefties to lefties this season, Lester got the most inside called strike. It was 16 inches inside from the center of the plate, with the runner-up one full inch less inside. In third was a pitch 1.5 less inside than the runner-up. You can ignore those weird blue dots down and to the left — those are PITCHf/x glitches I forgot to eliminate before saving the image file. Cameras. They lie, rarely.

Let’s look at another plot. This is Jon Lester pitching to lefties during the PITCHf/x era, going back to 2008:

Again, you should recognize the big red dot. This was by far the most inside called strike Lester has gotten against a lefty since at least 2007. Probably, it’s the most inside called strike against a lefty of his career. Previously, his most inside called strike against a lefty was 12.5 inches inside from the center of the plate. As a reminder, Monday’s strike was 16 inches inside from the center. That’s a difference of more than a quarter of a foot. And it’s not like the count was 3-and-0, when umpires tend to be forgiving. There were two strikes. This call was the difference between a walk and a strikeout in a close World Series game.

So how did this happen? We can go beyond just calling the umpire an idiot because it’s pretty much never that simple. I think we’re looking at three factors, ignoring any influence of Carpenter assuming the walk before it was granted. I’d like to think umpires aren’t quite that spiteful. First, here’s the third pitch of the plate appearance:

That’s another inside cutter, which was Lester either trying to get ahead in the count or get Carpenter jammed. David Ross set up inside, but he had to receive the ball a little more inside, and Miller identified it correctly. Here, Miller called the inside cutter a ball, but he was probably conditioned: If Ross set up inside again, and if Lester were to hit his spot, then Miller might be more likely to call that a strike. This demonstrated command, on Lester’s part. The next two pitches were away, and then Lester came back in.

Another factor is David Ross. Lester likes pitching to Ross, and Ross has been a highly effective pitch-receiver. Or framer. Whatever. Call it what you want to call it. Among the catchers who caught at least 1,000 called pitches this season, Ross was baseball’s sixth-best receiver. He was fifth-best at getting balls called strikes. Here he is, receiving the full-count cutter:

Ross is quiet, firm and comfortable. He catches the ball with his glove moving back toward the zone. Just watch the pitch and you kind of ignore how far inside Ross is set up. He just makes the pitch look a lot better. That is, except to Carpenter, who had a pretty good view himself. Carpenter wasn’t wrong in his assumption, but Ross made everything cloudy for everyone else.

Finally, and probably most importantly, a big part of pitch-receiving is command. Good framers generally can’t save pitchers who miss their targets, even if they still miss in or near the zone. Pitchers who locate make catching a whole lot easier, and Lester nailed his target dead-on. You can see that in the .gif above, or you can see that in the screenshot down below:

You see the target, and the yellow dot represents where the ball was caught. In a full count, it looks like Ross wanted Lester to throw a ball. Lester threw that ball, and he threw it perfectly. In fact, he threw it so perfectly it wasn’t actually a ball to the one guy whose opinion mattered. Lester couldn’t have located that pitch better. Lester was rewarded, on one hand, for throwing a ball. On the other hand, he was rewarded for flawless execution. The strike zone should still be the strike zone, but you can’t say Lester didn’t do what he wanted.

In all, we have an extremely inside called strike to a lefty from a lefty. It’s the most inside such called strike this season, and maybe the most inside called strike of Lester’s big-league career. It was set up, in part, by an earlier inside cutter that just missed a little more in. The pitch was located perfectly by Lester, and it was received well by Ross, and when you put everything together, Bill Miller saw enough to call Carpenter out. Carpenter couldn’t believe it, and he was correct, but the Red Sox had Miller convinced. Forward moved the baseball game.

It’s too bad for the Cardinals. The right call would’ve extended the inning, putting two on for a righty. That righty, however, was Shane Robinson… so, yeah. In rough win-expectancy terms, the call reduced the Cardinals’ odds of winning by about 5%. That’s important, and I don’t know what would’ve happened had Carpenter reached. Then again, I’m not here to complain. Lots of things could’ve gone differently. Everything could’ve gone differently. Things went how they went, and this particular called strikeout gave us something remarkable. Even at the end of October, Jon Lester accomplished a season-first. There’s nothing I can do to change the way you feel about that. I can just try to explain how something happened.