Corey Kluber’s Outing Reflected the Times

Larry Vanover was the home-plate umpire yesterday. At one point on Twitter I noticed he was trending, so, you probably know what that means. After one particular half-inning, Jon Lester walked over to Vanover to have a little chat, presumably to try to clear some air. There were disagreements. When the stakes are so high, it’s possible to see injustice everywhere.

Vanover, in truth, called strikes that were perfectly fine. There were borderline pitches, and any borderline-pitch decision will make half the viewers upset, but overall, the Vanover zone was good. Maybe great! Let’s use the artificially binary strike zone from Baseball Savant. During the season, 91% of the pitches taken within the strike zone were called strikes. Vanover called yesterday at 96%. During the season, 13% of the pitches taken outside of the strike zone were called strikes. Vanover called yesterday at 10%. More preserved strikes, fewer extra strikes. That’s good umpiring. He clearly missed a pitch or three, but that’s just part of the everyday arrangement. Sometimes I fall asleep without taking out my contacts. That’ll happen until we have lens-removing robots. (I, too, will not accept said robots until they are perfect.)

So, Vanover? Pretty damn good. Wasn’t the reason for anyone to complain about anything. Yet that doesn’t mean there wasn’t something interesting about the zone. I want to show you something, from Brooks Baseball:

That’s the called zone for Game 1 against lefties. If you go by the reference boxes, the calls were mostly terrific. There’s one pretty bad called ball against the Indians. What you might notice is that group of called strikes inside. You see a small wave of called strikes over the inner third, and much of that was Corey Kluber. Kluber had his two-seam fastball controlled so well that August went and wrote a whole article about it. Kluber dominated the ballgame for as long as he pitched, and perhaps his signature weapon was that front-door heater. August included example clips, and now I will do the same, because, who wouldn’t want to watch these again?

Thrown just so, those are almost impossible pitches. Kluber had them ending up at least catching the edge, so it’s not like he made the zone expand. But for a lefty, a two-seamer like that looks like it’s going to hit you, and hit you hard, right up until it runs the hell away. There’s not a lot a hitter can do to protect against that pitch. What you might hope, as a batsman, is that the pitch is called a ball. Vanover was granting strikes. And it turns out they’ve all been granting strikes.

You’ve probably read some strike-zone analyses before. There have been PITCHf/x studies of the zone stretching back at least to 2008, and one of the things we learned quickly is that, with lefties up, umpires have called strikes on pitches away, off the plate. They’ve been referred to as “lefty strikes,” and they were and are a part of our reality. But — okay, Jon Roegele is the strike-zone expert. Here’s an example of one of his tremendous research articles. Roegele has shown that the lefty strike zone has been shifted. For a while, lefties saw more called strikes away off the plate, and fewer called strikes in, over the plate. The outside strikes are gradually disappearing. And more recently, this has been compensated for. Umpires are opening up the inner edge. There are fewer strikes available away, but now it makes more sense to bust lefties inside.

It’s a pretty recent phenomenon. We’re talking something that has emerged over the last handful of months. It wouldn’t be a surprise to learn that, for example, maybe an umpiring memo was circulated around the All-Star break. This introduces some context to the Vanover strike zone. Vanover was granting Kluber, and others, those inside strikes against lefties. Those were always supposed to be strikes, but only more recently has the league reflected that. Those are strikes now more than ever, and Kluber and Roberto Perez saw that and took advantage of that.

I’m going to pull from Savant again. What Kluber was doing with his two-seamer — that was atypical. On the left, Kluber’s two-seamers against lefties during the regular season. On the right, Kluber’s two-seamers against lefties in Game 1.

In the past, Kluber mostly took the two-seamer away. Do that and maybe as a pitcher you can earn some ground balls. Tuesday was weird. Tuesday, Kluber got aggressive with the two-seamer inside. I’m not saying it was all about the strike zone; maybe Kluber just had unusually good feel for the pitch, and maybe this was a perceived vulnerability of the Cubs’ lineup. But Kluber, from the beginning, used his two-seamer to go after the inner edge. Neither the Cubs nor Vanover ever gave Kluber a reason to shift his own strategy. In the past, maybe some of those pitches would’ve been balls. Kluber would’ve had to adjust to that. In Game 1, he could go in there over and over again, and that allowed him to make the most of the pitch. Kluber’s fastballs have never been all that dominant. He’s also seldom been able to use them in the way he just did. It’s funny, but, the subtle league-wide trend toward more inside strikes on lefties could make Corey Kluber even better. As long as he throws like he was just throwing.

I don’t think anyone would’ve hit Corey Kluber on Tuesday. Good pitchers look their best when they constantly execute, and Kluber seemed to make fewer mistakes than normal. He was on top of his game, in other words, so the Cubs shouldn’t get too down on themselves. But in another year, perhaps the inside edge wouldn’t have been so forgiving. Those have always been rule-book strikes. Only more recently have they become more common actual strikes. Corey Kluber just pitched a game of the times. And so he was able to have the time of his life.