The Reds Have a Spin Rate Problem

With baseball’s annual winter meetings taking place this past week near Washington D.C, I want to take a look at the Cincinnati Reds and a potential way of looking to improve upon a historically bad pitching staff in 2016.  While they did just post the worst WAR by a pitching staff since 1900, they were completely average somewhere else, which likely aided them towards the path of history no team wants to make.  The Reds threw the highest amount of average four-seam spin-rate fastballs in 2016.

We are just scratching the surface on spin-rate research.  While we can’t say much for sure about ways to improve spin rate or why it differs from pitcher to pitcher, we do have a pretty good idea it’s good to be different.  The ultimate goal of pitching is to disrupt timing, create mis-hits and have swings and misses.  The more deception a pitcher can create by being further away from average spin on either the high end or low end of the spectrum, the better off they appear to be.  This was a major problem for the Reds last season as the they threw a whole bunch of average towards the plate.

Taking spin-rate data from baseballsavant.com, I looked at all 30 teams and their four-seam fastball data.  I set a minimum of 50 four-seams thrown by a pitcher to be included in the data set.  Team-by-team totals show that the Reds threw the fifth-most four-seam fastballs in 2016:

1. Rays: 10823
2. Diamondbacks: 10667
3. Marlins: 10606
4. Rockies: 10102
5. Reds: 9991

The average spin rate for the four-seam fastball in 2016 was 2241 revolutions per minute.  This season, the Reds pitching staff was pretty close to the MLB mean at 2232 RPMs. Only the Astros, Athletics and Mets were closer to the mean (2240, 2245, 2248 respectively).  Now, let’s create a bucket we will call “four-seams around average” and see what we collect. This bucket will include pitches that were 50 RPMs higher than 2241 and 50 RPMs lower than 2241 for a 100-RPM range of 2191-2291. Next, I’ll use data from the 10 teams closest to the MLB mean, the most “average” spin teams, to determine who threw the most “average fastballs.”  Here are the top five totals:

1. Reds: 3165
2. Mets: 2674
3. Athletics: 2072
4. Angels: 2056
5. Braves: 1973

As you can see, the Reds ran away with what we have designated as “average fastballs” with nearly 500 more than the Mets and over 1,000 more than the third-place A’s.  You could be saying to yourself that the Reds may have thrown so many average-spin fastballs because they threw the fifth-most four-seams in the majors this past season.  And you would be right since a larger sample size obviously affords the chance of more average pitches to be thrown (especially if the data follows a normal distribution like ours does). So I’ll bring in another measurement to further support that the Reds were very average in 2016: standard deviation

I’m sure most people are familiar with standard deviation (SD) so I won’t waste time going into formula, but an easy explanation is it’s one way of measuring dispersion in a given data set.  The lower the SD, the closer all the data points are to the mean.  Looking again at our 10 average spin-rate teams and the standard deviation for each team’s data set, here are the five lowest teams in terms of SD:

1. Reds: 123.99
2. Mets: 138.56
3. Angels: 142.838
4. Astros: 153.105
5. Cardinals: 157.645

There are the Reds leading the way again!  Let’s attempt to put all 10 teams on an even playing field by taking a sample of 1,000 four-seam fastballs from each group.  The mean of this sample is our random variable.  In R, we will use the replicate function to generate 10,000 of these random variables to learn about its distribution.  After running the simulation, the random variables follow normal distribution which is something we already knew.  What I was interested in is if the team with the lowest standard deviation would have changed after each team had the same sample size. Here are the lowest five teams in SD after 10,000 simulations:

1. Reds: 3.68
2. Mets: 4.106
3. Angels: 4.126
4. Astros: 4.472
5. Cardinals: 4.637

No change. By having the lowest SD in the group that was deemed to be the closest to the MLB mean in four-seam spin, and a test of a random sample of 1,000 pitches simulated 10,000 times, this further supports that the Reds pitching staff has a spin-rate problem, and is not just a product of a larger sample size.  In fact, the Reds had the lowest standard deviation of all 30 teams!

So where can the Reds look over the rest of the offseason to improve upon a pitching staff in need of upgrades in spin rate?  Well, a lot of the work in finding spin value from this year’s crop of free agents was done a few weeks ago on this site.  While Cincinnati won’t be in on the top-tier free agents available, there are more than a few options available that shouldn’t cost any more than $5-6 million in annual value that the Reds can afford to not only improve the bullpen, but move further away from the average spin that may have caused them problems all season.