Baseball’s Most Extreme Pitches from Starters, So Far

Introduction

After reading Jeff Sullivan’s piece entitled “Identifying Baseball’s Most Unhittable Pitches, So Far” on August 21, I found his methodology to be quite interesting.  It was suggested in the comments rather than looking at whiff rate we should consider who has allowed the weakest contact.  Now, there are a couple of different ways to look at weakest contact.  First, you could look at batted ball velocity.  You could also look at batted ball distance as well.  Both of these techniques would provide some measure of the severity of contact allowed by a pitcher.  At the end of the day though, a warning track fly ball is still as effective for a pitcher as a pop up.  I thought it would be better to look at who got hurt the least with their pitches.

In saying that, I mean to look at what pitchers are theoretically giving up nothing but singles on a pitch versus what pitchers are theoretically giving up nothing but home runs.  A quick calculation to quantify this value is total bases per hit allowed (TB/H).  This is the same as the ratio between slugging percentage and batting average (SLG/AVG).  Values have to be between one and four.  A value of 1.00 corresponds to only singles.  A value of 4.00 corresponds to only home runs.  Any value in between could represent a combination of all hit types.

Baseball Prospectus provides PitchF/X leaderboards for eight different pitch types: four-seam fastball, sinker, cutter, splitter, changeup, curveball, slider, and knuckleball.  I chose to look at only starting pitchers in this study.  Also, to be considered, a pitcher had to have thrown at least 200 of the pitch of interest.  The league leaders in games started are just above 25.  If we are conservative and estimate 80 pitches per start, that allows for 2000 pitches thrown, so 200 would represent roughly 10% of the pitcher’s arsenal.  With that background information now covered, let’s look at the best and worst pitchers in each pitch type.  All data is accurate through August 22.

Data

Four-Seam Fastball

Sinker

Cutter

Splitter

Changeup

Curveball

Slider

And for completeness,

Knuckleball

Combining all that data together, we get the following five pitches as the best in baseball so far.

Also, to complete the picture, here are the worst five pitches in baseball so far.

TB/H

Analysis

As you can see, there are a lot of “good” pitchers that throw “lousy” pitches.  This metric is far from perfect.  For example, Yu Darvish appears in the bottom five in two different categories.  Does that mean Darvish should stop throwing his sinker and cutter?  No, it most certainly does not.  It just shows that when Darvish makes a (albeit rare) mistake with either pitch hitters are mashing it.  I found this a fun exercise that yielded results that may not be the most meaningful but that are interesting for discussion nonetheless.