Seriously Though, How Is Brandon Woodruff Doing This?

Pitching analyst Lance Brozdowski has been on Brandon Woodruff since the Brewers right-hander returned from a 2023 shoulder surgery on July 6. Brozdowski has written about Woodruff twice, first breaking down the ways that he looks like a different pitcher this season. His second piece was titled “How Is Brandon Woodruff Doing This?” I’d like to really dig in and answer that question, both because when Brozdowski asks a question it’s usually a good one and because Woodruff’s numbers really are confusing. As Michael Baumann noted a few weeks ago, Woodruff’s return coincided almost exactly with Milwaukee’s recent unbeatable stretch. “If Woodruff is well and truly back,” Baumann wrote, “for my money he’s a bigger add than any starter who’s likely to get moved at the deadline.” Woodruff has gone 4-0 with a 2.29 ERA, a 3.73 FIP, and a 34.9% strikeout rate over his six starts, and he’ll likely be a huge part of the team’s playoff rotation, but whether he’s back is still very much an open question.

Before we get into everything, we should talk about Woodruff’s arsenal, which at least for a little while looked pretty different this season. A month ago at Brewer Fanatic, Matthew Trueblood analyzed Woodruff’s repertoire during his minor league rehab assignment, and wrote that in order to be successful, “Woodruff will need to reinvent himself.” The pitcher seemed to agree, at least at first. This season in the majors, he has thrown a four-seamer, sinker, changeup, cutter, curve, and sweeper. The cutter is new, with the sweeper replacing his traditional slider. However, he hasn’t thrown the sweeper since his second start (likely because it was the second game in a row the other team homered on the pitch), and he’s also drastically reduced his cutter usage over his last two starts. He’s also nearly evened out his fastball usage. In recent years, Woodruff led with his four-seamer, but now he’s throwing it 34% of the time and his sinker 31%, leading with the sinker against righties and the four-seamer against lefties. His curveball is down to 5% and his changeup has held steady at 17%. In other words, Woodruff is throwing a fastball 65% of the time, and that number jumps to 77% of the time if you count the cutter:

Let’s start with the reasons for suspicion, and please note that this section makes up five full paragraphs. Luck is a big component here. Woodruff is currently running a .143 BABIP and a 100% strand rate. Eight of the nine earned runs he’s allowed have come on home runs. Those are massively unsustainable numbers. The league averages a .289 BABIP and 72.5% strand rate. Even though he’s spent his entire career pitching in front of an excellent Milwaukee defense, Woodruff has never run a BABIP below .269 or a strand rate above 82% (except in 2023, when he only made 11 starts). No matter what else happens, we should expect his BABIP to add at least 100 points and his strand rate to drop by at least 20% going forward.

Woodruff’s fastball velocity is down significantly, which is not exactly unexpected after shoulder surgery. From 2019 to 2022, he averaged 96.4 mph on his heater. Before he got hurt in 2023, he was down to 95.9 mph. So far this season, he’s at 93.1 mph. According to Baseball Savant, that means he went from being in the 85th percentile in 2022 to the 29th percentile this season. He’s gone from having plus velocity to having – uh, is there a scouting word for the opposite of plus? – let’s say unplus velocity. It was a strength; now it’s a weakness. There’s no way for us to know whether Woodruff will get some of that velocity back over the long-term. Shoulder surgery is a big deal, and as a 32-year-old, we would’ve expected him to have lost some velocity by now anyway. Maybe it won’t come back at all, or maybe it will come back eventually, but we definitely shouldn’t expect him to be sitting 95 mph by October.

Woodruff has also lost significant movement on most of his pitches. His four-seamer both rises and runs less than it did in 2023. So does his changeup. His curveball drops less, and his sinker runs less and rises more. As you might expect, the stuff models are not thrilled about slower pitches that move less. In 2023, PitchingBot gave Woodruff’s stuff a 54 grade, while Stuff+ had him at 108. This season, those numbers are 41 and 96. With the exception of the new sweeper he’s thrown just seven times, both models think all of his pitches are worse than they were in 2023.

Reality seems to agree with the models. Woodruff’s 25.9% chase rate is his lowest since 2018. His groundball rate has absolutely cratered, from right around 38% in 2022 and 2023 to 26% this season. Not only is he allowing batters to hit the ball in the air, he’s allowing them to pull it in the air. That’s the most dangerous kind of contact there is, and among pitchers who have allowed at least 50 balls in play, Woodruff’s 23.4% pulled air ball rate puts him in the 92nd percentile, in a bad way. His 9.1% barrel rate is the highest of his career. Batters have an average bat speed of 72.8 mph against him, a mark that ranks 10th highest among the 438 pitchers who have thrown at least 400 pitches so far this season. Batters are seeing the ball and swinging from their heels.

We should also mention the competition. Woodruff has faced the Marlins and Nationals twice, the Mets once, and the Mariners once. Since the start of July, the Marlins, Mets, and Nationals have been three of the worst offenses in baseball, respectively ranking 24th, 25th, and 27th according to wRC+. The Marlins and the Nationals rank 24th and 27th in home runs this season, so it’s pretty disconcerting when they’re the ones making you look homer-prone.

Alright, that’s the end of the section. Those are all the reasons to worry that what Woodruff has done so far is unsustainable. Now it’s time for the reasons to believe, and the first thing I’d like to point out is that Woodruff was starting from a very high level. He’s been a genuinely great pitcher for years now, so although all those numbers I just told you about are worse than they’ve ever been, they also aren’t saying he’s garbage now. Stuff+ sees him as right around average, and PitchingBot expects him to have a 3.57 ERA, significantly better than the 4.12 mark that starters around the league have averaged this season.

Woodruff has also had his share of bad luck to go along with the good this season. So far, 17.1% of his fly balls have gone for home runs, the highest rate of his career. Now, he’s earned those homers – Statcast thinks he should have 6.5 homers rather than seven – but that doesn’t mean they’re not affecting his BABIP indirectly. Part of the reason Woodruff’s BABIP is so low is that when batters have hit the ball hard against him, they’ve hit it out of the ballpark, and those homers don’t contribute to BABIP. If you throw out the home runs, his xwOBA of .262 is among the lowest in the league, and his average exit velocity of 85.9 mph is also very good. So while his BAPIP is still unsustainably low, there’s at least a bit less luck involved than you might initially think.

Let’s look at Woodruff’s walk and strikeout rates next, because they’re both excellent. Despite the reduced stuff and the lower chase rate, his whiff rate is right around his career average, and his 20.9% called strike rate is the best of his career by a wide margin. So is his 69% first strike rate. As a result, his 34.9% strikeout rate is the best of his career, as is his 4.7% walk rate. If Woodruff can keep those numbers where they are, he’ll be a good pitcher even if he keeps giving up homers and his BABIP bounces up to normal levels.

Still, I’m honestly not sure how he’s earning so many whiffs inside the zone when his stuff looks so much worse, and I’m not sure how he’s earning so many called strikes. Here’s my best guess, though. The called strikes are coming almost entirely from his fastballs. Together, the four-seamer and the sinker have a 24% called strike rate. They’d never even hit 20% in any previous season. If you just look at pitches within the strike zone, that number jumps to 33.5% this season, once again a career high by a significant margin. I’m sure to some degree it has to do with the teams Woodruff has played – the Marlins and the Nationals rank 20th and 25th respectively in swing rate against fastballs in the zone – but it could also have to do with his pitch mix. While the loss of movement and velocity is undoubtedly a bad thing, Woodruff’s four-seamer and sinker now have a gap of 10 inches in terms of horizontal break, the farthest apart they’ve ever been. Add in the occasional cutter, and all of a sudden, when a batter picks up velocity out of the hand, this is the pitch movement they have to worry about:

The four-seamer goes straight, the sinker fades, and the cutter cuts. In other words, the ball could travel in either direction. That’s a recipe for hesitation and called strikes, and it could be the reason that Woodruff’s whiff and putaway rates on both his sinker and four-seamer are the highest they’ve been in years. The cutter doesn’t grade out well according to stuff models, but that doesn’t mean that it’s not making Woodruff’s other fastballs look even better.

In a similar vein, it’s not ideal that Woodruff’s sinker has more rise, but that does create more vertical separation between it and his changeup. Relatively speaking, the changeup suddenly has more drop, which could help explain the pitch’s dominance this season. It’s a small sample, but so far, it has a 38% whiff rate and just a 5.9% hard-hit rate.

Woodruff has always been an interesting pitcher. He’s so fastball heavy, and he’s not afraid to throw his four-seamer low in the zone. I’m really curious to see what he does next. It’s still so early for him. Will he bring back the sweeper that looked so promising? Will he keep phasing out the cutter? Will he throw the changeup more often now that it looks so dominant? Will he be able to keep pounding the zone with his fastballs, and will hitters continue to take them for strikes? As Michael Trzinski wrote at Brewer Fanatic last week, if Woodruff can keep this up, he looks like a genuine Comeback Player of the Year candidate. The Brewers have a more difficult stretch ahead of them, and as of right now, it looks like his next starts will come against the Pirates, Cubs, Giants, Blue Jays, Phillies, and Rangers. That’s a much tougher road than he’s traveled so far. It would be unreasonable to expect Woodruff to keep running a 2.29 ERA, but I don’t think we know what a reasonable expectation looks like just yet.