The Best and Worst Four-Seam Fastballs of 2013

Introduction

What is the best pitch of all-time?  Is it Mariano Rivera’s cutter?  Is it Randy Johnson’s slider?  Is it Walter Johnson’s fastball?  I do not know.  What I do know is that this question is nearly impossible to answer, so let’s simplify things a little.  What was the best pitch thrown during the 2013 regular season?  On a rate basis, PITCHf/x would lead us to believe that the best pitch thrown by a qualifying pitcher was Yovani Gallardo’s cutter with a wFC/c of 4.95.  In other words, for every 100 cutters thrown by Gallardo, he saved 4.95 runs above a pitcher who throws an “average” cutter.  What does this really mean though?  This system of calculation is based off the changes in run expectancy due to the outcome of each pitch, which is extremely complicated and tedious to calculate.  I felt that there had to be a simpler way to quantify the quality of a pitch. 

Background

Back in August, I posted an article entitled “Baseball’s Most Extreme Pitches from Starters, So Far” that posited the idea of total bases per hit allowed.  In other words, I wanted to look at who was getting hit the hardest.  Now, it was rightly suggested in the comments that this wasn’t the greatest way to determine a pitch’s quality.  For example, let’s look at the following two extremely hypothetical examples.  One pitcher throws his fastball exactly 100 times.  In those 100 pitches, he throws 99 of them for strikes.  On the 100^th pitch, he gives up a home run.  Now, by looking at TB/H, this pitch has a rating of 4.00, which is the worst possible rating.  However, he only gave up 0.04 total bases per pitch, which is excellent.  By comparison, the second pitcher throws exactly 100 fastballs as well.  He gives up 100 singles.  By TB/H, his fastball has a rating of 1.00, which is significantly better than the first pitcher.  However, he gave up 1.00 total bases per pitch, which is awful.  If a pitcher gave up a base runner each time he threw a pitch, he probably would cease throwing that pitch very quickly. 

That got me to thinking that total bases per pitch may be a much better way to determine the quality of a pitch, but there are also glaring problems with this method as well.  For example, 100 balls thrown in 100 pitches would a value of 0.00 total bases per pitch.  Clearly, a pitcher’s ability (or inability) to throw a pitch for a strike needed to be incorporated as well. 

Proposed Solution

To try and solve the problems suggested above, I propose the following simple formula:

adjTB/P = [1B + 2*2B + 3*3B + 4*HR + xBB] / Pitches

where,

xBB = Balls/4

With that said, I know some pitches are thrown out of the strike zone intentionally (i.e. the waste pitch).  At the end of the day, a waste pitch only puts you one step closer to walking a batter and adds one pitch to the pitch count.  Every coach would prefer their starter to throw a Maddux each time out, so efficiency is the name of the game.  In order to test this formula, let’s look at a sample calculation.

According to Baseball Prospectus and their PITCHf/x leaderboards, A.J. Burnett threw 614 four-seam fastballs this regular season.  On those 614 pitches, he allowed 10 singles, nine doubles, five home runs, and had 202 of those pitches called balls.  Burnett allowed 58 total bases and 50.5 xBB.  Doing some quick arithmetic, he allowed 0.1767 adjTB/P. 

At first glance, I’m sure your reaction is similar to my initial reaction.  Okay, so what does that mean?  On its face, a correct response may contain the words “I’m not really sure”.  If we look at the summation of each four-seam fastball thrown by starters this year, we find that the league allowed 0.1800 adjTB/P, so A.J. Burnett threw a slightly above average four-seam fastball this year.  To come to that conclusion though, you’d have to know both a player’s rate and the league rate.  We can present this information in a much nicer and easier to understand way. 

To do this, I decided to turn to the old standby from every scout in baseball, the 20-80 scale.  As you’re probably well aware, the 20-80 scale attempts to rate a player’s skills numerically.  50 is average.  60 represents exactly one standard deviation above average.  30 represents exactly two standard deviations below average, and so on and so forth.  By taking the weighted standard deviation of the data set, we can determine how many standard deviations above or below average a certain pitch is.  Looking at the full season data, the weighted standard deviation for four-seam fastballs is 0.0262 adjTB/P.  Another quick calculation tells us that A.J. Burnett rated as 0.13 standard deviations above average.  Converting that on a 20-80 scale rating, Burnett’s four-seam fastball gets a rating of 51.  On quick glance, the 51 rating makes much more sense than 0.1767 adjTB/P, which helps solve one of our problems.

Results

Now that we understand how to calculate the values and what they mean, let’s look at a scale for whose four-seam fastball really excelled and whose really was problematic.  To qualify for the full season, 600 total four-seam fastballs had to be thrown.  This gave me 103 qualified starting pitchers.  The Top 10 qualified starters were:

 

For comparison, the Bottom 10 qualified starters were:

 

On a monthly basis, a minimum of 100 four-seam fastballs had to be thrown.  The best and worst pitches each month this season were:

 

Only three starters qualified as above average in each month of the regular season.  Their monthly ratings are shown below.  No starter qualified as below average in each month this season. 

 

I plan to continue this study by analyzing both other pitch types and relievers.  Baseball Prospectus provides data for the following pitches: four-seam fastball, sinker, cutter, splitter, changeup, curveball, slider, screwball, and knuckleball.  At the completion of all the pitch types, I’ll post the ratings for complete repertoires as well.  If well-received, I’ll try and provide monthly updates as next season rolls along.