On the Shrinking Strike Zone and Lengthening Games

For the last few years, Jon Roegele (among others) has been doing excellent work showing that the strike zone was getting larger with every passing season. Specifically, pitchers and catchers had started getting calls on pitches below the knees that they hadn’t gotten previously, and the rise of the called low strike led a pervasive myth that hitters had`gotten too passive, putting the onus on the batters for the decrease in run scoring, when the reality is that batters were being called out on pitches they couldn’t do anything with anyway.

With strikeout rates again at an all-time high, MLB has apparently decided to take some action after a few years of studying the issue. According to a Jayson Stark report from last weekend, the competition committee approved a tentative plan to “effectively raise the lower part of the strike zone to the top of the hitter’s knees”, beginning as early as next year, assuming the rules committee also approves the plan, and the issue will apparently be raised with the players during CBA negotiations, so they may have a voice in the changes as well.

And you can be sure that some of those players won’t be happy about the proposal. For instance, here was Adam Wainwright’s reaction to the report.

“It’s a horrible, horrible idea,” he said. “One, I’m a pitcher. And I’m a pitcher who likes to keep the ball low. Two, and mainly, all this talk about making the games shorter — what part of raising the strike zone up is going to do that? … They want more offense. I understand that. But taking 45 seconds off for an intentional walk one out of every three games isn’t going to make up for the added balls in the gap by raising the strike zone, in my opinion.”

At least Wainwright is honest and admits his bias right up front. This is a change that could potentially make his job harder, and like most self-interested individuals, he’s against things that have a negative consequence for him personally. But note that Wainwright doesn’t just stop at saying that he’s against it because he’s a pitcher, but he’s against it because he thinks it’s counterproductive to MLB’s other stated goal, which is to reduce the length of games back under three hours. As Wainwright and others would have you believe, instituting a smaller strike zone will lead to even longer games, and so MLB is barking up the wrong tree.

Except that the evidence suggests that this probably isn’t going to be the case.

Using Roegele’s data on the strike zone, here’s a table showing the size of the strike zone every year since 2009, as well as the average time of an MLB game for each of those same seasons.

Strike Zone Size and Game Length
Year Strike Zone Size (sq in) Time of nine inning game
2009 435 2:51
2010 436 2:50
2011 448 2:51
2012 456 2:55
2013 459 2:58
2014 475 3:02
2015 478 2:56

If Wainwright’s hypothesis that shrinking the strike zone would make games meaningfully longer, then the reverse would also have to be true; expanding the strike zone directly lead to shorter games. Except, during the expanding-strike-zone era, games have gotten much longer, adding nearly 10 minutes to the average game since the zone started getting bigger. I’m not suggesting there’s causation here — the expanding zone isn’t the reason for the lengthening games — but there’s not much evidence that the size of the strike zone is the determining factor in how long games go. It is not nearly as simple as smaller zone = longer games.

Now, that isn’t to say that a smaller strike zone won’t have any effect on the length of the game. As I discussed last week, a percentage of the increase in game length from last year to this year can be accounted for by the extra pitches per at-bat players are seeing this year, and with walk rate spiking up this year as games have gotten longer, it’s certainly possible that moving the zone back to where it was a few years ago will bring another increase in pitches thrown.

After all, players aren’t robots, so even if they know the zone is going to be raised in the rulebook, pitchers are going to have to see the changes for themselves, and you can bet they’ll be testing the bottom of the zone next year until umpires prove that it really has changed. And if pitchers are throwing more pitches in an area that will be called balls, we probably will get even more walks, and more hitters-counts, leading to an uptick in baserunners, which adds time to a game.

But this effect can easily be overstated. At the height of the PED era, the year 2000, when teams were scoring 10.3 runs per game and everyone hit could hit the ball out of the ballpark, the average game featured 78.3 plate appearances, about three more hitters per game than we see these days. Offense was plentiful, the strike zone was smaller, and yet, the average nine inning game only lasted 2 hours and 57 minutes, almost exactly the same as it was last year. Over the last 15 years, through various changes, the league managed to trim two runs per game in offense without actually making the games any shorter.

Essentially, MLB has traded higher levels of scoring for more time between pitches and more pitching changes. This the league’s version of the Shelby Miller trade, and it should be pretty clear why the commissioner would rather not keeping making that exchange if they don’t have to. The goal isn’t to try and get everyone out of the ballpark as fast as possible; it’s to try and make sure there aren’t overly long lags between entertaining plays, and while Adam Wainwright might find a called strike below the knees exciting, a lot of other people do not.

But the most important thing to remember in this proposal is that MLB is not proposing instituting a new strike zone; they’re proposing the roll back of changes that have already happened. This is an unchange, if that’s a word. The zone expansion has already happened, and the unintended consequences of that change are now being addressed by walking back the expansion that has already occurred. This is the league taking away a benefit that pitchers haven’t had before and don’t need, similar to closing a tax loophole for rich people.

The game, as currently played, skews towards the pitchers. The increases in velocity and specialization make their jobs easier than ever before; they don’t also need a larger strike zone than pitchers before them got. And MLB’s approach to the pace-of-play issue is a multi-prong strategy, focusing on getting the players to reduce the time between pitches, which should more than offset any additional pitches added to the game through a reduction in the strike zone.

With all due respect to Adam Wainwright, it’s not a “horrible, horrible idea”. It’s actually a very good one, and it probably won’t result in a meaningful lengthening of games played. It’s perfectly fine for Wainwright to say that the change will hurt him personally and therefore he’s against it, but his suggestion that it’s bad for the game as a whole is pretty likely to be proven wrong.

Dave is the Managing Editor of FanGraphs.

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6 years ago

this season, more of a belly itcher