Can Pitchers Control Their BABIP by Controlling Pitch Location?
At the PITCHf/x summit I gave a presentation about making the type of contour and heat maps that I often show here. In the presenatation I listed some of the things one could do with such maps and I said 'for example you can see how BABIP varies by pitch location.' A questioner at the end of the talk asked if I had done so. He thought if BABIP did in fact vary by pitch location, and pitchers can control the locatoin of their pitches then pitchers could control their BABIP. I, at that point, had to fess up that it was just an example and I had not in fact looked at it. Unfortunately I don't know the name of the person who asked the question, but here it is.
There is a long history of examination of how much control a pitcher has of his BABIP (batting average of balls in play). The first major work was by Voros McCracken who, in 2001, suggested that pitchers do not have the ability to prevent hits on balls in play. In 2003, Tom Tippett found that some pitchers, in particular knuckleballers, had the ability to suppress hits on balls in play throughout their career. In addition, the BABIP of a ground ball is higher than that of a fly ball and we know pitchers do control their ground ball rate. So, we should expect BABIP differences between ground ball and fly ball pitchers. The general understanding, at this point, is that pitcher's have some, but probably a very small, amount of contrl over their BABIP beyond their control over batted ball type.
Obviously pitcher's control the location of their pitches, so if BABIP varies by pitch location could this be how some pitcher's have the ability to depress their BABIP? Let's see how BABIP varies by location. Here I am just looking at RHB.
There is some trend for pitches down in the zone to have a higher BABIP. I am sure this is driven by the fact that high-BABIP ground balls are more likely on hits low in the zone while low-BABIP fly balls are more likely up in the zone.
EDIT: In my initial post I had the outside/inside orientation flipped in my interpretation. Below I have corrected that. I would like to thank Mike Fast for bringing this to my attention and apologize for any confusion this might have caused. As always the images are from the catcher's perspective.
Along the horizontal axis pitches in the middle of the plate have the highest BABIP, which is not surprising. Beyond that, though, on pitches low in the zone those inside have a higher BABIP than those away, and pitches up in the zone those away have a higher BABIP than those inside. For those down in the zone, which will most likely be ground balls, those inside pitches will be pulled and pulled ground balls to the left side of the infield are more likely to be hits. On pitches up and in are most likely to be home runs, which are not counted as balls in play. This might be partially responsible for the drop in BABIP up there. Also maybe these pitches 'tie up' the hitter causing popups which have a near zero BABIP.
I wanted to examine the horizontal gradient further, so I took a one-foot-high band of pitches centered at y = 2.5. My hope is to see how much the BABIP changes by horizontal location to see if it is reasonable for a pitcher to depress his BABIP based on the location of his pitches. Again this is just for RHB.
So there is definitely a trend. The farther inside a pitch is hit the lower the BABIP. But look at the error bars the BABIP is effectively unchanged from x = 2 to x = -0.5. A pitch really has to be on the inside fourth of the plate before there is a significant drop in BABIP. From there to outside the zone away there is a big drop in BABIP.
It looks to me for a pitcher to seriously decrease his BABIP based on the horizontal loation of his pitches he either needs to induce swings (and contact) inside of the zone or be able to locate on the inner fourth of the plate.
If a pitcher could regularity locate pitches in the string zone, but just on the inner edge he could drastically lower his BABIP. I am not sure there are a lot of pitches with the control to pitch with the speed and movement required to get out major league hitters AND locate the ball that finely. If they miss too much to one side it is a ball, too much to the other it hits the heart of the plate. The one pitcher, off the top of my head, who I think might be able to do this is Mariano Rivera. Check out the location of his cutters to RHBs.