With Aaron Civale making his return tonight I found a column on Fangraphs from April 6 in which he was one of the pitchers featured. I don't know if it's been posted before. It deals with using technology to evaluate pitchers' "stuff".
Aaron Civale, Cleveland Guardians
PitchingBot Stuff: 39, 128th among starters
Stuff+: 116, 18th among starters
Now here is a disagreement. PitchingBot thinks Civale has almost no stuff to speak of. Stuff+ thinks that he’s one of the nastiest starters in the game. What in the world is going on here? In a word, it’s everything. The two systems disagree across the board on how effective Civale’s raw pitch metrics are.
Let’s start with his two fastballs. They’re not going to grade out incredibly well by either measure, sitting in the low 90s without extreme movement, but PitchingBot hates them. It gives them grades of 26 and 28 on the 20-80 scouting scale. Stuff+ is more sanguine; it checks in at 76 and 101 on a plus-stats scale. That’s not a huge deal, because Civale mostly relies on a cutter, but it explains some of the disagreement.
Both models like Civale’s cutter just fine, though PitchingBot thinks it’s slightly below average while Stuff+ thinks it’s slightly above average. The biggest disagreement of the whole bunch is in his curveball, which everyone agrees is good. The question is how good. PitchingBot thinks it’s a 60, comfortably above average, but Stuff+ happens to think it’s the second-best curveball in baseball, behind only Taijuan Walker’s. I can see it; it’s a truly fearsome hook. It gets both more drop and more horizontal movement than average, and it’s not even that slow for a pitch with that much movement.
On the other hand, that’s the only swinging strike that Civale garnered out of 20 curves, and he also only landed one for a called strike. You might be tempted to write the pitch off given that. But this is one great strength of pitching models: they look at the raw building blocks rather than what hitters did against the pitch on a single day. Civale’s curveball looks mostly the same as it did last year, when it had a 19.7% swinging strike rate. It looks mostly the same as it did in 2021, when it had a 14.8% swinging strike rate, and in 2020, when it had a 19.7% swinging strike rate. The Mariners did a great job against it, but that doesn’t mean it’s not a good pitch. It’s reasonable to expect good season-long numbers given that we have a mountain of data suggesting that this pitch shape works for him.
The truth on Civale is probably somewhere between the two models...I’ll direct your attention to Graham Ashcraft, who is fourth in Stuff+ and 27th according to PitchingBot’s Stuff grades, as a similar case. Modeling baseball pitches isn’t easy. That doesn’t mean that it’s not useful, though, and I hope this was a helpful look at the way our leaderboards work.
The rest of this season will be crucial for Civale, if I'm not mistaken. The Guardians have a wave of talented young starters beginning to surface and Civale has been injured five times in the last two years. None of those times were fluke injuries like being struck with a batted ball. It's been different things; a finger, a forearm strain, an oblique strain, and a hammy.
Civale needs to make every start the rest of the season and show he can get hitters out with an average at best fastball and cutter plus a wipeout curve. Otherwise he won't be in the plans going forward.