MLB teams are always looking for an edge on their opponents. Recently, the shift has become more and more popular, and teams have become more and more aggressive on the appearance of their shifts. In the past few seasons we’ve seen whole sides of the infield emptied out as well as 4 man outfields.
This shifting isn’t done without thought. Much of the shifting strategy is based off of spray chart data that reveals hot and cold spots on the field. Using common sense, teams place their fielders in those hot spots, and they leave the cold spots empty. I imagine managers say things like, “Why put our 3rd basement in a spot the batter hits it to <1% of the time? We could put him in THIS spot where he hits it to 40% of the time.”
Obviously, not all players are candidates for shifts. Players with very even spray charts like for instance, Whit Merrifield are poor candidates to shift defenses against, since they balance their batted balls to all fields.
One of the primary shifts employed by teams is the infield pull shift. You know the one. The one where the infield looks something like this for righties, and the mirror image for left handed hitters.
Since this shift is so common, I have decided to focus my analysis on the pull shift, and candidates that would be well suited for an increase (or decrease) in those shifts. To confirm this is a good methodology, I examined the correlation of % of balls a batter pulled to the % of times the defense shifted on that batter. If this is a good idea, I would expect to see correlation between the two.
Okay, so the correlation isn’t amazing, but it’s there! Clearly the players who pull the ball more see more shifts than those who pull the ball fewer times, as expected. With this in mind, let’s take a look at the top 10 players with the biggest increases in Pull % from 2018 to 2019.
All of these players are pulling the ball more than last season, and thus are candidates for increased shift frequency from defenses. Since I don’t want to bore you and break down all 10 guys, I’ve highlighted two players here. Max Kepler and Marcell Ozuna exemplify prime shift candidates for the 2019 season. The particular reason I’ve highlighted them is that one has seen a lot of shifts this season, and the other hasn’t. Lets go back to that figure I showed a moment ago, and find Max Kepler and Marcell Ozuna on the chart.
As you can see, Max Kepler has seen many more shifts this season than Marcell Ozuna. No qualified hitter has pulled a higher % of his balls in play this season than Max Kepler, so it is understandable that he sees a lot of shifts. Ozuna has also pulled the ball a lot, but has seen relatively few shifts. If both Kepler and Ozuna are pulling the ball at high rates, what is the difference that generates such a disparity in shift rates?
The answer is in the ground balls. Since most shifts are in the infield, ground balls are the primary point of concern for most managers looking to shift on a particular batter. Let’s take a look balls with a. projected distance of less than 200 feet, which Baseball Savant considers balls hit to the infield (or at least can be caught by an infielder).
Just 7% of Kepler’s infield balls go to the left side of the infield. ONLY 7%!!!! Ozuna has a more modest 25% go to the right side of the infield. Although Ozuna has pulled a lot of balls, his spray chart on the ground is more balanced in the infield than Kepler’s. Kepler pulls the ball 73% of the time on the ground, while Ozuna pulls the ball just 55%.
Ozuna’s relative balance on infield balls has made him difficult to shift the infield against. He will remain an outlier on that plot as long as this continues; however, we should keep our eyes on this, and expect an increase in shifting against Ozuna if this were to change. Marcell Ozuna has all of the features of a player we would expect to become a prime shift candidate, but teams seem to believe that the time to shift isn’t quite right. It will be interesting to see if this trend continues over the end of the season, or if an increase in shifts is forthcoming.