Taking a cue this week from fellow BtBSer Neil Weinberg, let's riff on an infrequently discussed aspect of pitching that doesn't lean too heavily on mathematical gymnastics and will also build off of some of my work in recent weeks, that looked at quantifying the best and worst pitches of last season.
The home run, while a hitter's best friend and a surefire way to please the ladies, can be hell on pitchers. Certain pitchers have issues with the round tripper. Sometimes it comes from a difficulty missing the middle of the plate with the fastball or a repertoire that gives them a propensity to allow the long distance popup. These pitchers are easily located by sorting by the HR/FB% or even the HR/9 columns of the baseball stats website of your choosing. However, let's go one further, with the help of the PITCHf/x Leaderboards over at Baseball Prospectus, and figure out if there is one particular pitcher/pitch pairing that is conducive to offensive fireworks, at least for starting pitchers, in 2013.
For this quick exercise, we will look at starters, as previously mentioned, with at least 500 pitches thrown for a given pitch. Between the starting role and the pitch cutoff, we will have a suitable sample size without the fear of any outliers in the data; with at least 500 pitches, we are certain to be fairly resistant to bad luck or weird slumps that might skew the results. Also with this cutoff, we are left with a sampling of pitchers that are implicitly faithful to the pitch and live and die by the offering. From there, we will look at each of the pitch types and use some quick math -- number of pitches divided by home run -- to see who is the most affected by the gopherball, in the form of the stat pitches per HR.
The verdict is pretty damning for John Danks, who sits atop our list with two offerings conducive to being taken for a ride, in the form of his four-seam fastball and changeup. We also see some damning results for changeups, with the pitch showing up frequently in our table. Another idiosyncrasy is Aaron Harang's sinker not having much sink to it. Looking at the supplementary batted ball type per ball in play columns, we also find, not surprisingly, that most of these pitches are easily elevated. One caveat to this is Wade Miley's slider, which has an exceptional 59 percent groundball rate despite its occasional deposit beyond the outfield walls. Even Danks' changeup appears to be an occasionally effective pitch, as nearly 50 percent of the offering end up as grounders. However, we do find an underlying theme of pitch location possibly exacerbating this trend; hang a slider, or especially, a changeup, and it is ripe for ripping.
Let's flip the table upside down and take a look at who does a great job with keeping a particular pitch inside the park:
One thing you will see missing immediately is the HR column -- all of these pitch/pitcher combos did not yield a dinger in 2013, which is pretty impressive. Also impressive is Tyson Ross and his six percent linedrive rate on his slider to go with a ridiculous groundball rate. One small surprise is the lack of sinkers in the group, with only Joe Kelly's offering making the cut for this table. Regardless of pitch type, we find the common thread of a high grounder rate with our no homer group.
While this exercise doesn't display or explain all of the variables at play with a given pitcher's propensity to give up homers, it does tell us one thing -- if you're looking for a souvenir, catch a John Danks start.