Schwellenbach made his debut, and early on he looked really good by the eye test. My old grading metrics are several years old and likely out of date for modern pitchers, so I'm going to do this a little differently and rank each aspect of his pitches compared to all pitchers who have thrown at least 10 of that pitch this season. Rather than using positive and negative values for movement, I'm going to follow Baseball Savant's convention of Vertical Movement without Gravity (which can be negative if the spin actually creates additional sink), and ARM/GLV direction for horizontal movement. Then rather than trying to grade based on standard deviation, I'll just give the rank compared to all qualifying peers.
FA: 95.9 mph (93 of 498), 12.3" Vert (454 of 498), 5.1" Arm (392 of 498)
This FA falls into that group of fastballs that used to confuse people 20 years ago when a guy threw hard and they couldn't figure out why he still got smashed. The movement profile on this FA is definitely an issue, and he should not be throwing it 34% of the time.
CU: 79.9 mph (92 of 203), -4.7" Vert (173 of 203), 10.3" Glv (80 of 203)
The CU is also nothing to write home about, and it has more slurve action than the traditional downer action we see from guys like Fried.
SL: 86.8 mph (199 of 402), -5.1" Vert (10 of 402), 5.2" Glv (172 of 402)
This is the pitch he will have to rely on to get guys out, and he should probably be throwing it more than 19% of the time. So far it's his only plus pitch.
FC: 91.8 mph (30 of 206), 8.8" Vert (141 of 206), 1.8" Glv (118 of 206)
A cutter with good velocity and mediocre movement is something that can be relied upon. I expect it will tunnel pretty well with that slider, and it will also help the 4-seamer play up.
CH: 83.9 mph, -1.5 Vert (14 of 313), 8.3" Arm (308 of 313)
This is a very interesting change, and it's too bad he only threw it 5 times. It seems to move like a traditional splitter with straight down movement that must appear to fall of the table. This pitch has the potential to be a real problem for hitters.
Overall: I think what stood out on TV was the velocity and the good slider, and I commented on the slider during the game thread. It is definitely his best pitch. The FA needs to be spotted and used more sparingly while the FC and SL carry the majority of the workload. The curve doesn't seem to bring much to the table, and it's really just a slower slider, so like most pitchers who throw both there isn't really a point. If he can dial in that change the batter will have a very hard time deciding what to swing at between the slider and change.
Without the change he's pretty much a slider specialist out of the BP. With the change at full strength he can probably turn the lineup over a couple times and be a solid 3/4. As always, elite command can make all these pitches play up, but it's too early to tell on that.
So what's happened since?
FA: 96.0 mph, 13.4" Vert, 5.7" Arm
He's maintained the velocity on this pitch while adding 1" of rise and 0.5" arm-side run. He has also reduced his usage to 26.8% from 34%, which is exactly what I wanted to see happen with this pitch.
SL: 87.0 mph, -3.7" Vert, 4.2" Glv
This was his only plus pitch, and I wanted him to throw it more. It's now his 2nd most used pitch, but it has taken a step back in movement profile.
FC: 92.7 mph, 9.6" Vert, 1.7" Glv
This pitch was solid, and now he's added a tick of velocity to it. This should be his workhorse pitch that makes everything else play up. I wonder if throwing this harder and more often has caused him to lose some bite on the SL.
CU: 80.3 mph, -6.7" Vert, 9.3" Glv
He's added 2" of downward movement to this pitch, which makes its movement profile more different from the SL than it was previously.
FS: 84.3 mph, 0.5" Vert, 9.4" Arm
I described his change as a split, and now it's being classified as a split. He barely threw it, and now he throws it 14% of the time. I said it had potential to be a problem for hitters, and now it's a problem for hitters.
SI: 95.1 mph (114 of 512), 6.7" Vert (362 of 512), 14.9" Arm (275 of 512)
This pitch is new. He only throws it 7.5% of the time. It is an average sinker and is another average pitch hitters need to worry about.
Overall
Schwelly reduced the usage of the mediocre FA, refined the the break on his CU, increased the usage of his good SL, learned to rely more on the downer Split, added velocity to the quality Cutter, and added a decent Sinker...then paired it all with excellent command. This is how a guy goes from a 3/4 to a 2/3 by "learning how to pitch". I don't think it's unreasonable to argue about him possibly growing into a legit TOR now with his .274 xwOBA showing how good he's been. Sale at .258 is a bonafide CYA caliber Ace, and Schwelly is definitely in the realm of a #2 without the track record to declare him legit just yet.