The Joe Sheehan Newsletter: Behavior Modification
Vol. 15, No. 44
June 1, 2023
Though it’s the start of a new month, I’m going to skip a recap of the league stats and how the new rules are affecting gameplay. I’ll do another check-in during the summer. In recent weeks, we’ve seen the rate of pitcher injuries, once a crisis, slow a bit, a boon to the case for the pitch clock. Jason Collette of Rotowire tracks the league stats every day, and you can follow him for updates.
Today, let’s dig in on one aspect of what MLB is trying to do, change hitter behavior. The restrictions on defensive positioning, as I’ve written many times, stem from a misreading of recent trends. Hitters aren’t reacting to the defense, the defense is reacting to the hitters. The hitters are reacting to the pitchers, who are so difficult to hit that the correct approach against them -- the run-maximizing approach, the win-maximizing approach -- is to value power over contact.
Let’s engage with the argument on its own terms, though. Ben Lindbergh, over at The Ringer, had an excellent piece about strikeout rate in which he interviewed Morgan Sword, the executive vice president of baseball operations at MLB. Sword is one of the architects of the new rules, and while I disagree with what he and MLB have done, I know him to be a thoughtful guy who very much wants to make baseball more entertaining. In his words:
“I don’t think it’ll be the whole solution, but it does make sense to me that over time, increasing the value of putting the ball in play will increase the frequency with which the ball is put in play,”
I’ve referred to this as the double-bank-shot theory. MLB sharply restricted what defenders could do this year, changing the game from “hit ‘em where they ain’t” to “hit ‘em where they ain’t allowed,” to some effect. What we call the shift, and certainly the shift as angry old people would describe it, consisted of putting extra players to one side of second base and a fourth outfielder in short right field. Here’s what that change has done for left-handed batters:
Success! (BA on pulled batted balls by left-handed batters, 2022-23)
2022 2023 Diff
Ground Balls .147 .186 +.039
Line Drives .661 .691 +.030
Combining these, the shift restrictions have been worth 37 points of batting average to left-handed batters on balls that, last year, were more often gobbled up by shifted defenders. It’s part of an overall jump of eight points of batting average compared to 2022’s first two months, and a ten-point leap in batting average on balls in play. As many others have observed, this rolls batting average back about five years, to 2018. I personally don’t think that’s enough benefit from such a radical philosophical change, but your mileage may vary.
When any hitter comes to the plate, there are a lot of potential outcomes. Walks and strikeouts, for sure. They can be hit by a pitch or lay down a bunt. Most of the time, though, they swing away and make contact. When they do, they can hit the ball in one of nine ways: ground balls, line drives, and flyballs; pulled, hit straightaway, or to the opposite field, in various combinations. With modern data collection, we have perfect information on what happens when a player does any of those things.
The fundamental problem for Sword and his staff is that what they want hitters to do is far from the best thing hitters can do.
Output (BA and SLG on batted balls, 2023)
BA GB LD FB
Pulled .205 .694 .474
Straightaway .246 .620 .208
Opposite .406 .621 .175
SLG GB LD FB
Pulled .241 1.088 1.686
Straightaway .251 .793 .588
Opposite .443 .821 .406
The single most valuable thing a hitter can do is pull a fly ball. Now, I’m statting this up because it’s 2023 and you pay me for it, but it’s not like this was some mystery unlocked by a Dodgers staffer in 2016. Trying to hit the ball hard and far has been a part of baseball since the 1870s. You look at the baseball stars from the period between the start of the National League and 1893, when the mound was set at 60’6”, and they’re the guys who had the highest ISOs, guys like Dan Brouthers and Roger Connor and Buck Ewing. The numbers don’t look that impressive to us today because they were hitting balled-up socks with tree trunks and the parks didn’t allow for automatic homers, but hitting for power has always been valued highly. Even in the Deadball Era, from 1901-10, your Hall of Famers are your leaders in ISO, Honus Wagner and Sam Crawford and Nap Lajoie.
The difference between pulling a fly ball and hitting a grounder up the middle, even with the defense hobbled, is 230 points of batting average and 1400 points of slugging. Even hitting a line drive up the middle is a little worse than hitting a fly ball: .620/.793 versus .474/1.686. The difference is so large that it’s worth wearing an increased strikeout rate to try to hit pulled fly balls.
Let’s go back to Sword for a second.
“What you’re trying to do is change what’s rewarded at the highest level so that effect filters down all the way through the giant baseball system around the world.”
This is an impossible task within the framework of baseball as we know it. The value difference between pulling a fly ball -- hitting any fly ball -- and hitting a ground ball is so great that nothing currently on the table, not even the execrable “pie slice” rule, will be enough to change hitter behavior. You would have to take fielders off the diamond, or put a balata ball in play, or have two-strike strikeouts, to make it more profitable for hitters to hit ground balls instead of fly balls. It’s the way the engine of baseball works. The runs are in pulling fly balls, and everything else doesn’t work as well.
The shift restrictions, which MLB seems to think will get players to hit more ground balls, do the opposite. Pulled ground balls, and to a lesser extent pulled line drives, are the waste produced by trying to hit pulled fly balls. Last year, hitters would be punished for failing at their primary goal by defenses positioned to turn the batter’s failure into an out. Now, those batters are rewarded. Because of this, they’re committing even more to that approach.
Doubling Down (process stats, April-May, 2022-23)
FB% Pull% K%
2023 37.1% 40.9% 22.7%
2022 36.8% 40.5% 22.3%
Batters are hitting more fly balls, they’re pulling the ball more, and they’re striking out more under the new rules, because the new rules reward the dominant style of hitting, and the dominant style of hitting is the the way to win baseball games.
If you want to change hitter behavior, you have to deal with the pitchers. Until then, MLB is just making things worse.
