Clusters in the Outfield (Part 2)
Last week in this very space, I used cluster analysis to try to quantify a hitter's spray chart. Commenter "Nightfly" asked, "Are the sample sizes for switch-hitters large enough to run a comparison of, say, Victor Martinez against himself, from each side of the plate?" So instead of comparing hitters to each other as I did last time, I'm going to juxtapose players against themselves. I ran the numbers to see which switch-hitters had the biggest gap between cluster centers, grouping by handedness. It turns out, Carlos Beltran is a pull hitter from both sides of the plate, which forces outfielders to shade five yards in either direction depending on whether he's batting righty or lefty. And to answer your question, Nightfly, no, Victor Martinez cannot throw out baserunners.
I changed the color scheme and symbols of the graph at the suggestions of commenters Studes and Alex, and as always, I'd appreciate any advice on how to improve the visuals provided.
That outfielders position themselves differently based on the batter's handedness is intuitive, but what other more subtle clues might improve outfielder positioning? Rich Lederer and commenter Fat Ted suggest I incorporate PITCHf/x data into my analysis.
For the upcoming analysis, I'm going to adhere to Peter Jensen's advice that I only look at balls that were caught by outfielders which improves the accuracy of the data but limits the sample.
First, I looked at how batted ball location fluctuates based on pitch type. It turns out that an outfielder only has to move several feet in general if he knows whether a fastball (two-seam, four-seam, cut) or an off-speed pitch (curve, slider, change, split, knuckle) is coming.
Juan Rivera, a right-handed batter, is one player who really gets around on off-speed pitches.
Meanwhile, Miguel Montero, a left-handed batter, nearly broke my clustering algorithm with his inability to pull fastballs. A visiting right fielder might fare just as well turning balls in play into outs by positioning himself in the Chase field pool when Montero is gearing up for a fastball.
I also looked at patterns dealing with pitch location by splitting the plate into halves. In addition to the fact that batters tend to go the other way with outside pitches and pull inside pitches, Balls on the outer half are also driven slightly farther than balls inside
Some hitters, like Jacoby Ellsbury and Ian Kinsler, can't drive inside pitches the other way with authority, which I imagine would be useful information to outfielders.