Atlanta Braves RP Daysbel Hernández has been good, but unsustainably so.

On this very website, we’ve used many words to bemoan the Atlanta Braves running into bad luck, whether that be Chris Sale’s BABIP over his first handful of starts or Matt Olson’s actual stats lagging well behind his actual stats. But, like every team, the Braves have also gotten some unsustainably lucky performances, and Daysbel Hernández’s season to-date might be the luckiest of them all.

There was a good bit of chatter online about Daysbel after he walked in a critical insurance run against the Phillies on Tuesday night. That appearance (1 IP, 2 H, 2 BB, 1 ER, 2 K) raised his season ERA all the way up to 1.96 (gasp!). A 1.96 ERA is obviously excellent, more than you could hope for from a player around Memorial Day in his first full year in the big leagues. But, even before Tuesday’s appearance, there was plenty of cause for concern in Daysbel’s profile.

Daysbel has always been known to be effectively wild. In the minor leagues, Daysbel had a 2.98 ERA and 3.54 FIP in 108.2 IP from 2021-2024. Despite an inflated 13.3% BB in that time frame, Daysbel found success by striking out 31.8% of hitters with his high 90s fastball and wipeout slider and limiting home runs. In his time with Atlanta last year, Daysbel remained that same guy, posting a gaudy 35.1% K and allowing 0 HR to offset an ugly 13.5% BB and ultimately post a sterling 2.50 ERA and 2.49 xERA in 18 innings of work. His 29.7% CSW and 14.5% SwStr were both indicators that he had very really swing-and-miss stuff that would play at the highest level.

This year, Daysbel has still has been among the best in the league at limiting damage on contact (93rd percentile barrel rate, 81st percentile hard-hit rate, 0 home runs allowed), and he’s still wild (17.2% BB), but he’s no longer missing bats at a meaningful clip. His K% has plummeted all the way down to 19.4%, with the CSW (27.0%) and SwStr (10.9%) following suit.

The velo and movement of his stuff is all similar to last year, so it’s hard to pinpoint why this is the case. Location+ attempts to measure a pitcher’s command, and Daysbel has dropped from a 93 to an 89 from 2024-2025 in that regard (league average is 100), so that may be part of it. His overall Zone% is about the same as last year, but his O-Swing% (chase rate) has dropped from an above-average 35.4% to one of the lowest marks in the league at 25.5%.

That’s probably where this all starts – hitters just aren’t as tempted by his pitches out of the zone, and swings on pitches outside the strike zone are more likely to generate whiffs than swings on pitches inside the zone.

Pitch Profiler measures the magnitude of a pitcher’s misses by defining the middle of the plate as the ”heart zone,” the area right around the edge as the “shadow zone” (roughly 50/50 chance of called strike), a bit off the plate as the “chase zone,” and further than that as the “waste zone.” Take a look at what % of Daysbel’s pitches ended up in each zone in 2024 vs. 2025:

(If you are on a mobile device, this table is best viewed in landscape mode.)

I wondered if part of the reason why Daysbel isn’t getting as many chases is that he’s thrown his slider in the waste zone too often, but that doesn’t seem to be an issue. The increase in fastballs in the waste zone won’t help him, but that’s also not enough to explain why his O-Swing% has dropped by about 10 points.

So, I’m at a bit of a loss as to why MLB hitters aren’t chasing or whiffing vs. Daysbel like they did last year. He’s still throwing just as hard as he did last year, and there haven’t been any significant changes as to how he’s locating. I haven’t seen any evidence that he’s tipping pitches or anything. Perhaps the 18 innings from last year simply allowed hitters to develop a more concrete gameplan vs. him.

Regardless, I’m hoping that Brian Snitker ignores that 1.96 ERA for now and rolls with other options in high-leverage. There just aren’t any examples of pitchers who are successful in a large sample size with a K-BB% under 5%. The Braves bullpen isn’t exactly chock-full of fellas who give you warm fuzzy feelings, but until Daysbel gets the strikeouts going again, I’d place Raisel Iglesias, Pierce Johnson, Dylan Lee, Aaron Bummer, and Enyel de los Santos ahead of him on the depth chart.