Tuesday, August 3, 2010

Strike Three Swinging

It took awhile, but I'm going to finally get to post about baseball (it is, after all, by far my favorite sport). I was able to read values from the PITCHf/x database and plot pitch charts directly from R. Somehow, reading articles about PITCHf/x these past few years, though exciting, is not the same as actually being able to do my own PITCHf/x analysis. So it's definitely amazing to finally get into the game.

Batters getting fooled swinging on strike 3 appear on Sportscenter all the time it seems, whether it's a high fastball out of the zone or if it's a slider low and away. Whatever the case, a swinging strike on strike 3 is one of the most exciting plays in baseball, and I wanted to take a look at all of the swinging strike 3 pitches (strike 3 swinging pitches?) on four-seam fastballs, changeups, curveballs, and sliders. Let's take a look at all swinging strike 3 pitches from 2007-2009, categorized by pitch and by handedness (from the catcher's perspective):

Here's four-seam fastballs on strike 3 swinging. As expected, many of the pitches lie up in the zone, blowing hitters away out of the strikezone, the type of pitches batters like to call "rising fastballs." Batters also whiff a lot on pitches from righthanded pitchers painting the upper lefthand side of the strikezone away for righthanded batters (righthand side for lefthanded batters), and vice versa from lefthanded pitchers.

Changeups are offspeed pitches, and they're shown here as low and out of the zone as well, sometimes low and away. Compared with fastballs, changeups seem to drop when they're not supposed to, and so are ideal pitches to induce a swinging strike, most of the time after a fastball. Whereas the four-seam fastball is mainly used to blow a hitter away even when the hitter sometimes knows it's coming, changeups are usually used as deception pitches, acting like they rise and come quickly as fastballs, but actually drop and slow down, causing batters to swing much too early.

Much like changeups, curveballs tend to get the batter out on strike 3 while low and away. In this case, the "away from the batter" factor kicks in, especially in the same handedness matchups of RHP vs. RHH and LHP vs. LHH.

Finally, sliders have the most horizontal movement of all of the above pitches, and therefore, can paint the outer sides of the strike zone and beyond it in order to get a batter to whiff on strike 3. It looks like righthanded pitchers love to use the slider to get the final strike on a righthanded batter, locating the slider low and away sometimes, but most of the time just away. And vice versa, the low-and-away slider works well for lefthanded pitchers against lefthanded hitters, while a slider coming towards the batter in an opposite handedness matchup does not seem to favor the outside of the strikezone as much as a same handedness matchup.

Once I figure out how to produce filled contour plots for pitches like the basketball shot location heat maps (with Dave Allen and Jeremy Greenhouse as prime examples), the differences between different plots will be more resounding. Until then, straight up scatter plots of pitches will have to do.

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