I’m going to go through all 30 starting rotations, sorted by fewest runs allowed, within the lens of pitch movement synergy. Please read that article first, as these notes assume the reader has the context from that article.
Shane Bieber
Absolutely perfect synergy almost to 0.18 seconds on both planes, for 4 pitch types. It’s just incredible, and it’s why Bieber can be successful even with reduced velocity. This is reflected in the swing decisions batters are able to make:
Putting aside the 47 changeups he threw, Bieber is extremely deceptive on the FF and SL, and about average with the cutter. However, the curveball (KC = Knuckle Curve) allows pretty good swing decisions on average. Let’s take a look at that and see how it compares to Wainwright’s curveball:
Let’s contrast that to Wainwright:
Having a bigger “bump” on the vertical plane may be important. Sub-theory number 72 is that having a ton of movement differential makes it really hard for the batter to guess ball/strike, which is why “eephus” type pitches can still work from time to time. Cardinals list is next, and we’ll look into Wainwright in more detail then.
Triston McKenzie
The fastball-slider pair has excellent horizontal synergy, maintaining perfect synergy for about 0.10 seconds before diverging. On the vertical plane, there is room for improvement, where imparting more initial downward velocity on the slider, would not only improve vertical synergy, but also improve late vertical separation.
We see the synergy reflected in good, but not great ability to induce bad swing/take decisions. Let’s talk about the curveball:
We see a small amount of clear separation between the pitches, but not the extreme movement differentials that Wainwright has. We’ll add Triston to the bucket of non-deceptive curveballs. He also isn’t tipping a specific pitch via his arm angles/release points:
Cal Quantrill
Quantrill should be showing great deception numbers given the synergy betwen his cutter and four seamer, except that he doesn’t, because he is primarily throwing sinker-cutter:
This is not a commentary on the quality of the FF vs the SI, but, from a late separation and synergy standpoint, the FF/FC pair looks much much better than the SI/FC pair.
Fortunately, the SI/CH is a great pair synergistically:
It also looks like the Guardians pitchers all throw a curveball shaped like this:
I assume Cleveland knows what it’s doing with pitching development, so will look into this some more later. I don’t know if Quantrill really has the margin of error to change his approach, but it’s possible that a FF/CH/FC mix would up his strikeouts, based on the late vertical separation he would get, with stellar early synergy.
Or he can continue posting 6.5 K/9 numbers and hope he’ll be a useful pitcher.
Aaron Civale
I don’t think that Civale has good synergy on any of his pitches. The only idea I have to explain the poor quality swing decisions batters are taking is his arm angle variation:
Zach Plesac
Plesac has great synergy between the CH and SL:
The fastball also has good synergy, but he has almost no vertical separation. Visually, we can see the issue with the fastball, from a “stuff” perspective.
If we focus on the FF/SL pair on the vertical plane, we see decent synergy; Plesac looks like he would get a lot more swing and miss if he could find a way to add some IVB to the fastball by changing his release to improve vertical synergy, and via spin to increase the late vertical separation.
Fixing the early path of the FF would also improve its synergy with the changeup, improving deception and stuff quality.
Concluding Thoughts
Shane Bieber has amazing synergy on his pitches, and should be a very good pitcher, no matter the velocity he has (to a point). Triston looks like he has a couple of tweaks that might help him get to another level. The rest of the rotation are great examples of what mediocre stuff looks like, but perhaps, maybe, there are a couple of tweaks there too.