Ranking the best pitches on the Royals in “Bauer Units”

Driveline Baseball has pioneered a new way to help pitchers train and better develop their pitches. If you’ve never heard of Driveline Baseball, that’s okay. Unless you’re something of a baseball nerd you probably don’t take up much interest in the latest pitcher training and development strategies. But what CEO Kyle Boddy and his crew at Driveline are doing is pretty impressive, and even if you don’t agree with everything they do (I don’t necessarily, it’s okay to disagree and still respect what they’re doing), it’s always good to acknowledge new information when it’s presented to you. Check out this video to understand their new term “Bauer Units”:

Easy enough, right? RPMs / MPH = Bauer Units. For a fun experiment, I’m going to break down the Royals in terms of the top three Bauer Units on each pitch. First, I'm going to make some predictions before looking at any raw data. Remember, just because someone throws super hard, doesn't mean they’ll have more BU’s. Velocity will work against you in this experiment if you don’t have a high spin rate. Here are my predictions for the Royals leaders in BU by pitch:

4-Seam Fastball:

1. Jason Adam
2. Ian Kennedy
3. Kelvin Herrera

2-Seam Fastball:

1. Jake Junis
2. Brad Keller
3. Jason Hammel

Curveball:

1. Eric Skoglund
2. Danny Duffy
3. Jason Hammel

Slider:

1. Jake Junis
2. Danny Duffy
3. Kelvin Herrera

Changeup:

1. Kelvin Herrera
2. Danny Duffy
3. Jake Junis

Overall:

1. Junis - Slider
2. Adam - Fastball
3. Duffy - Curveball

Calculating actual results........and here are the actual results:

4-Seam Fastball:

1. Jason Adam - 27.6
2. Ian Kennedy - 26.3
3. Brian Flynn - 25.3

2-Seam Fastball:

1. Ian Kennedy - 26.1
2. Brian Flynn - 25
3. Blaine Boyer - 24.8

Curveball:

1. Scott Barlow - 33.1
2. Jason Adam - 32.7
3. Blaine Boyer - 32.6

Slider:

1. Brandon Maurer - 33.2
2. Kelvin Herrera - 31.5
3. Scott Barlow - 30.6

Changeup:

1. Danny Duffy - 29.2
2. Ian Kennedy - 23.8
3. Kevin McCarthy - 22.8

Overall:

1. Brandon Maurer - Slider - 33.2 Bauer Units
2. Scott Barlow - Curveball - 33.1 Bauer Units
3. Jason Adam - Curveball - 32.7

Reactions:

1. I underestimated how many Bauer Units breaking pitches would register. I expected them to register more RPMs than the average fastball, but I did not expect the difference to be that great. I mentioned in a previous article that Royals fans ought to be patient with Brandon Maurer because of his raw stuff, and Bauer Units back me up. Maurer’s slider is filthy, and if he ever learns to throw it with command he has a chance to be special.
2. Ian Kennedy’s appearance at or near the top of the fastball lists shouldn’t be surprising. Kennedy has a well above average spin rate on his fastball, and only throws it 90-92 mph, a good formula for BU’s. As much as I don’t like the general approach that Kennedy takes to the mound with him, his 4-seam fastball has some really nice spin to it and gives it the illusion that it is rising as it reaches home plate. When in reality, high spin rates just mean that the ball doesn't drop as much as a pitch with a lower spin rate.
3. As soon as my co-writer, Patrick Brennan, is done calculating his z-scores for Royals pitches, we’ll be able to get you a better understanding how/if Bauer Units have a direct correlation to pitch effectiveness. Until then, I can tell you that the early results are promising. Brandon Maurer’s slider, the top Royals pitch in terms of Bauer Units, has a .000 slugging percentage against in 2018. Here is a graph of Royals sliders in terms of Spin Rate and SLG% with color added to give you a general sense of the average velocity of the pitch:

This isn’t strictly Bauer Units, but you can see how spin rate on a slider has a small correlation with SLG% against. Brandon Maurer and Kelvin Herrera, the top two Royals pitchers in both spin rate on their slider and in Bauer Units, also have two of the lowest SLG% against on their sliders.

Conclusions

The jury is still out on the correlation between Bauer Units and effectiveness of a pitch. Given that Brandon Maurer and his top Royals BU score, it appears that location on a pitch indeed still matters. It doesn’t matter how filthy your slider is if you can’t throw it where you want it. Blaine Boyer has gotten some pretty good tilt out of his curveball so far in 2018, but it’s also been getting rocked by opposing hitters. Once Patrick and I get done correlating z-scores with BU’s we’ll have a little better understanding, but for now it’s fun to just rank the pitches with a new metric that I would guess most people have not heard of yet. Let us know what you think in the comments.