What Do the Differences in Corbin Burnes With Orioles Tell Us About the Brewers?

Corbin Burnes has been everything the Baltimore Orioles had hoped he would be this season. Only six starting pitchers have pitched more innings so far in 2024, and only six have a better DRA-, according to Baseball Prospectus. Burnes is 6-2, with a 2.26 ERA and 76 strikeouts. Of his 13 total starts, 10 have been quality starts. He is, in some ways, enjoying a better season than he had in either of his last two campaigns with the Brewers.

That's no reason for the Brewers to worry much. They knew Burnes might have a great season in Baltimore when they decided to trade him, and they should be very happy with their own side of that deal so far. Joey Ortiz is in the running for the NL Rookie of the Year Award, and soon, the team will get to make use of the extra draft pick they acquired as part of the deal. Whether Burnes is good for the O's or not will only matter if they and the Brewers meet in the World Series, at which point it would be hard to call either side a loser in the transaction.

However, we should still stop and take a close look at what's happening with Burnes, because it tells us some important things about the way the Brewers approach pitching--and what is both great and questionable about it. Stylistically, Burnes is a different pitcher in 2024 than he was in a Brewers uniform, in a way that reveals the divide between the Brewers' philosophy of pitching and that of another team known to be near the cutting edge in pitching instruction and development. 

Late in his Brewers tenure, almost two-thirds of Burnes's pitches were his hard stuff. He doesn't throw a four-seamer anymore, but the cutter and sinker accounted for roughly 64 percent of is offerings. This season, they're barely showing up more often than you'd expect by flipping a coin. He increasingly leans on the curveball and slider, at the expense of the harder stuff.

Normally, you see this from a pitcher when they're trying to generate more whiffs and are willing to work outside the zone a bit more, but Burnes has been very aggressive since making his switch, and it's led to a dramatic reduction in walks and home runs, but also a steep decline in strikeout rate. Burnes remains an above-average starter in terms of strikeout rate, but he's much more of a contact manager this year.

Burnes already did well at limiting exit velocity from opposing batters, but the rate at which batters hit it 95 miles per hour or harder has dropped even lower than it was with the Crew. I recently created a statistic called Harmless Contact, which (separate from exit velocity) gives the percentage of batted balls against a pitcher that left the bat at either a trajectory lower than -10 degrees or one higher than 45 degrees, where contact is almost as useless as striking out. Burnes's Harmless% sat in the mid-30s for each of the full seasons since the pandemic while he was with Milwaukee. So far in 2024, that number has jumped to a league-high 40.1%.

It's strange to see Burnes throwing more strikes and getting weaker contact while varying his pitch mix so much more. It's harder to fill up the zone with four or five pitches than with two or three, and it was always assumed that Burnes's hard cutter neutralized hitters' power when he located it well. It's turning out that, perhaps, it's something more than that, because he's turning to softer stuff and still getting lots of weak, ineffectual contact.

Absent any other info, it would reflect poorly on the Brewers that a player would go elsewhere and start doing these types of things better. Having lots of other info, though, we can say with conviction that the Brewers are very good at inducing weak contact, too, as a team. They just have a very different approach than do the Orioles, in terms of how to mix pitches to effectively chase either strikeouts or non-threatening contact. Consider Colin Rea, the very model of a kitchen-sink starter, and compare his pitch mix to that of Burnes, before and after leaving the Brewers.

Rea is mixing pitches much more than Burnes, but in the end, he's throwing more hard pitches (the sinker, cutter, and four-seam fastball) than Burnes is. As a team, the Brewers throw one of those three pitches 61.0 percent of the time, second-highest in MLB. The Orioles, by contrast, use four-seamers, sinkers and cutters just a combined 56.9 percent of the time, 14th in MLB. The difference is that the Brewers are comfortable with--and at times, even insistent upon--having pitchers use multiple fastball looks. 

Burnes has cut way down on his sinker usage and entirely eliminated his four-seamer. Rea, along with pitchers like Bryse Wilson and even relievers like Joel Payamps, has stuck to using multiple heaters. That begets a lot of mishit balls, and some called strikes. It's not a recipe for elite peripheral numbers, absent elite talent. The Orioles are more in line with modern orthodoxy, and Burnes has looked more like a typical modern ace this year than he did last season. Still, the Brewers get nearly as much out of their less expensive, less famous pitching staff as the Orioles and other theoretically optimized teams do.

There are many ways to skin a cat. As long as the outs keep coming, it's ok to be agnostic about which approach works better, and why. The Brewers are still fighting to maintain sufficient pitching depth this year, and their below-average team strikeout rate indicates that there might be trouble ahead. So far, though, despite trading their ace this winter and replacing him with cheap and damaged arms, the Brewers still boast a good pitching corps. That's a credit to their front office, their coaching staff, and their catchers, as well as the pitchers themselves, and it's a reminder that not everything about baseball has to evolve in the same direction in order to survive.