Brandon Pfaadt Regression. Worry About Spencer Schwellenbach?
Brandon Pfaadt, Spencer Schwellenbach, Hunter Dobbins
DBacks Brandon Pfaadt had a regression start yesterday (4.2 IP, 7 H, 6 ER, BB, 6 K) and is still tinkering against left-handed hitters. Early in the season, he pulled a lot of his away-targeted fastballs back over the middle-down portion of the zone (spoke about this here). In his last 3 starts, he’s cleaned that up and is mostly sitting middle-up with occasional away locations. The Kepler HR he allowed yesterday was an up-in fastball target that missed arm-side back over the plate, something he didn’t do much last year per his heatmaps. His sinker is also making a comeback versus lefties, too. He threw the pitch just 8% in his first 4 starts. That has climbed to 22% in his last 3 outings, mostly driven by big usage on April 22 against the Rays. 🐍
Pfaadt has a new curveball, which is 3 mph harder with a much tighter shape than his 2024 curveball. FanGraphs Stuff+ upgraded it from a 94 last year to a 102. He threw it 17% to lefties in his first 3 starts… and gave up 4 home runs. Perplexing, as the shape looks good to me, and the HRs weren’t egregious misses. Usage of the new curve has ticked back to 10% in his last 3 outings. Is it too similar to the sweeper shape? Is it just a high-variance pitch? Swing-miss on it to lefties still looks great even with 4 barrels allowed.
Pfaadt’s season line puts my head in a blender. Swinging strike looks ok… but net strikeout rate is down. Zone rate is down… but his walk rate is down. Sitting on a ~3.80 ERA after 7 starts. Despite the variance and change, the projections (kinda) look like a copy of 2024? Which wouldn’t be bad!
Braves Spencer Schwellenbach has run into some trouble in his last 3 starts (3.2 IP, 8 H, 6 ER, BB, 4 K yesterday). He gave back some of the vertical break gains he showed in his first ~4 outings, now sitting just 1” higher than last year and up about 1 mph. But the bigger question mark has been and is his approach to lefties. He’s pulled his four-seamer down from 42% to 30% in his last 3 starts. He’s throwing the pitch inside less as well, perhaps connected to more cutters on the inner-third in his last 3 outings. In last night’s game, he threw his cutter 32% to lefties, a career high. Lefty cutters were something he threw a lot when he debuted, but backed off as his 2024 progressed. 👍
Given his four-seamer’s batted-ball performance versus lefties this year and how much zone it has been catching, I think more cutter makes sense for the time being. You can see his fastball drifting away from lefties below. I was a bit lower than the industry on Schwellenbach to start the season. With his four-seam shape improvement and velocity jump, I realized I was going to be wrong. I think he settles out to around a top-30 pitcher rest of season, which feels like a split between those bullish on him and me kind of fading him. The evolution of his lefty approach could help him tap into more upside. The answer there might be a bunch more sliders. The lefty tinkering is encouraging, and I’m not too worried about his recent blip.

Red Sox Hunter Dobbins has a 3.78 ERA / 4.14 FIP in his first 3 starts. He’s a classic cut fastball type, sitting 94-95 with 16” vertical break and just 1” arm-side movement (8” is average). He has a high arm angle at 54° (~40° is average), but his release height isn’t too high because of his 6.5’ extension (comparable to Justin Slaten, actually). Dobbins is mostly four-seam, slider, sweeper to righties with four-seam, curveball, splitter to lefties. He hasn’t allowed a barrel to a righty bat in his 3 starts. He looks a lot like Fitts, Kutter, and the rest of the Red Sox higher-slot arms that have bubbled to the surface these past 2 years (north-south version of Houck/Bello). ✂️
Dobbins flipped to a splitter from a changeup entering his 2023 season and then added a sweeper entering 2024. The current splitter he’s throwing seems to have developed last season around July/August. The prior iteration was slower with much less arm-side movement (sitting in cut-split territory). His current iteration is a 90-mph monster with a drop-run uncommon for his arm angle (grip below). It’s my favorite pitch in his mix. He’s probably not going to run big strikeout rates, but he’s historically been hard to barrel, so the net here should be around a league-average pitcher. Impressive to get that out of an 8th-rounder.
I would lean that Pffadt’s CB shape is too close to the Sweeper in terms of horizontal. So he might run into a hard hit problem.
I would still throw it given it’s shape I really do like it but seems it’s just a variation off his sweeper really which can still work maybe just need to be sequenced better?
Do you think with Schwellenbach he could just go Cutter in and Slider or Splitter down to LHBs feels like his splitter should play a more prominent role but also I understand that pitch is not going to be in the zone really. The putaway rate is definitely lower than the slider as well so I’m all for ripping more sliders down.
But what of Marlin Max Meyer? 14ks to 0 is a story I need to read about. #injured?