Home Run Rate by Pitch Location
So far I have looked at the run value of a pitch based on its location as it passes the batter's plane. Today I am going to take a slightly prosaic break from that and look at everyone's favorite contributor to run value: the home run. Below are maps of HR rate per pitch by pitch location. Again I average over pitch type, count and speed, so there are some obvious limitations to the analysis. The number presented at the top of each figure is the average HR rate per pitch.
Since the batter's handedness is more important than the pitcher's I averaged across the rows above to create just two maps, one for RHBs and one for LHBs. Over the composite map I plotted all the home runs for an individual hitter to see how he compares to his peers. Here are the HRs of everyone's favorite HR hitter, Jack Cust, plotted over the composite LHB map. Cust's home runs are, for the most part, where you expect for a left-handed batter: the highest density slightly in from the center of the zone, none in the down and away corner of the zone and more above the zone than below.
Here are two other batters I thought were particularly interesting. Alfonso Soriano is almost a caricature of a right-handed batter with his highest HR rate region even more down and in than expected. Carlos Pena, on the other hand, mashes outside pitching and the inside half of the zone has surprisingly few HRs. A possible explanation for this pattern could be that Pena just gets very few inside pitches because pitchers know he is a dangerous HR hitter. This shows one problem with my analysis. I am comparing the composite HR rate to a player's raw HRs not adjusted for the number of pitches a player sees in that region. I should be comparing that player's HR rate to the composite rate. For two reasons I did not do this: (1) I am having a hard time creating rate maps for individual players based on so few HRs and (2) even if I had such a map I cannot think of an effective way to overlay the two rate maps (individual player and composite) as nicely as I can overlay the actual HRs on the composite rate map. But it is something I am going to think about and work on in the future. |
Comments
You know who's not surprised about the near-zero hr rate down-and-away?
Leo Mazzone.
Posted by: will at March 17, 2009 7:13 AM
These articles are great, Dave! I look forward to seeing more of your work.
Posted by: Mike Fast at March 17, 2009 7:48 AM
Dave,
Great work here. I have a couple questions about massaging the data to create a continuous matrix for R's contour plotting function. Do you have an email address posted where I can contact you?
Thanks!
Posted by: JP at March 17, 2009 1:22 PM
Thanks Mike,
I am glad that you enjoyed them.
Posted by: Dave at March 17, 2009 2:59 PM
Really cool, although I expected color.
One idea I never followed thru on is first identify hr% by location (and pitch type and count), as you have done here, then for each hitter (his favorite zones and pitches to go deep) then finally see how well each player recognizes the mashable pitches - what are the swing% for batters when they see a pitch in the best hitting zone? My opinion is that Barry Bonds and Brian Giles hit a high pct of homers because of superior pitch recognition, and putting the bat on the ball when they swung, not because of hitting the ball an extra-ordinary distance.
Posted by: Brian Cartwright at March 17, 2009 3:52 PM
Brian,
Yeah, Rich, suggested I do color too. For some reason I liked the gray-scale. There is a link at the bottom of this comment to an example of what they look like in color, I think all the red was off putting to me.
That is a really interesting idea, looking at how a batter's swing percentage by location correlates with his HR rate location. My next post will look at something similar, comparing swing percentage by location and run-value of hit pitches by location. But it will average over all hitters.
http://img17.imageshack.us/img17/4479/custalt.png
Posted by: Dave at March 17, 2009 4:25 PM
Interesting plotting, but be wary. As in the Pena reference, in making inferrences because his plotting doesn't fit the "norm." There are some hitters who simply hit different zones better then others, and can "work" that location out of a pitcher by a variety of box methods, such as box depth and proximity to plate, varied further by degree of closed to open stance.
I see you quickly surmise that charting pitch type as a variable would make for an interesting study. Of course, the variables never end, as even amongst LHP and RHP there are every degree of arm slots. But lots of fun, for sure. Cool stuff.
Posted by: chetthejet at March 17, 2009 5:15 PM