Aaron Ashby is on a historic radiator

Aaron Ashby didn’t have his best season in 2026. He pitched a ton: He finished tied for sixth in the league in appearances, and only Houston’s AJ Blubaugh topped his 87 bullpen innings this season (Ashby added 2 1/3 more in just one opening appearance). Ashby’s 89 1/3 total innings are his most in a season since 2022, when he was primarily a starter; he had only pitched 95 innings in the big leagues total since a shoulder injury cost him the entire 2023 season. This action – arguably excessive – somewhat undermined Ashby’s effectiveness starting in 2025, when he was one of the best relievers in baseball:

Ashby was evolving, however, and the underlying metrics suggest he wasn’t actually a lesser pitcher in 2026 despite more walks and a slight decline in results. Its “Stuff+” metrics, which attempt to quantify how “bad” a pitcher is, were mostly kept in 2026; his sinker and slider, two of the best pitches in the majors in 2025, were a little worse, but his curveball and changeup were both a little better. Its Statcast profile in 2026 shows as much red as in 2025; in both seasons, Ashby ranked among the elite in ground ball percentage and barrel percentage. In 2026, Ashby was at least in the 88th percentile for overall expected batting average, expected ERA, whiff percentage and strikeout percentage – all higher than last season. His average fastball velocity went up a notch, from 97.4 to 97.7 mph.

So while Ashby’s ERA was a point higher and an increase in walks created occasional problems, Ashby’s stuff was just as good as the previous season, with about 40% more innings. Watching Ashby wasn’t always a comfortable experience this season — his command came and went and his 10.7 percent walk rate was higher than in any previous season — but his pitches were essentially as difficult to hit as ever.

Maybe it shouldn’t have been a surprise, then, what we saw from Ashby in the playoffs.

Ashby pitched in three of four games against the Padres in the NLDS. He went multiple innings in two of those three outings and picked up a win in the deciding Game 4 series when he went three scoreless, hitless innings to tie the game for starter Robert Gasser with the big guns in the back of the bullpen, Abner Uribe and Trevor Megill. In those three games total, he pitched 5 2/3 innings, allowed two hits and two walks, allowed no runs and struck out five.

During the Dodgers’ sweep, Ashby also pitched in three of four games. In a close opener, Ashby pitched the seventh and eighth runs in a one-run game and allowed only one walk. He had saves in Games 2 and 4, and his performance in Game 4 – he pitched the final three innings, and twice, with the tying run in the third with one out, got out of trouble – will go down in Brewers lore. His full numbers against the Dodgers: 6 2/3 innings, two hits, one walk, six strikeouts.

Through two series, Ashby started six of Milwaukee’s eight games. He totaled 12 1/3 innings; he has one win, two saves, he has allowed four hits, three walks and no runs, and he has struck out 11.

This race is entering historic territory. There’s a whole other series to play, and who knows what’s going to happen, but: There have only been 26 instances in postseason history where a pitcher has gone at least 12 innings with an ERA below 1.00. If you want to bring the ERA down to zero, where Ashby currently is, there are only six more:

Ashby is already at or near the innings pitched total of all these guys. He’s in relief ace territory at this point, and there’s a real argument that he should have won the NLCS MVP; the cinematic nature of Jake Bauers’ exploits on the show probably won him over, but Ashby was certainly just as deserving.

Ashby’s work this postseason so far reminds me of two other players from the not-so-distant past. The first was another highly regarded prospect who didn’t function as a starter but became, briefly, a reliever and a major playoff figure: Andrew Miller. At the age of 26, Miller was a top-10 prospect; he had already pitched nearly 300 major league innings in various roles, and he had been traded twice — once as the anchor in one of the biggest trades of the 2000s, when the Tigers traded him and others for Miguel Cabrera and Dontrelle Willis. Miller struggled as a starter, but finally found success in his seventh season when he became a full-time reliever; over the next five years, Miller was as good as any relief pitcher in baseball and played major roles on several postseason teams. The 2016 campaign, however, was the most magical: in 19 1/3 innings over 10 appearances for Cleveland, Miller allowed three runs (a 1.40 ERA), struck out 30 batters and walked just five. For his entire postseason career, Miller allowed just four runs in 38 2/3 innings, giving him a lifetime postseason ERA of 0.93.

The other player that comes to mind is Wade Davis, another top prospect who failed as a starter but eventually made it as a full-time reliever. Davis was drafted by the Rays, but it didn’t work out; he was traded to Kansas City as part of the James Shields trade, but had a disastrous 2013 season as a starter. In 2014, the Royals put him in the bullpen…and over the next four seasons, Davis posted a 1.45 ERA in nearly 250 innings. In the 2014 postseason, Davis allowed one earned run and struck out 20 in 14 1/3 innings in 12 appearances as a setup man, including 10 innings of a 0.00 ERA across the ALCS and World Series. The following season, when Kansas City won it all, Davis did not allow a run in eight appearances; he struck out 18 and walked three in 10 2/3 innings, the Royals won every game he pitched in and he got four saves and a win.

From a storyline perspective, I remember Davis and Miller dominating postseason talk for those three years in the mid-2010s. The idea that the role of starting pitchers in the postseason was diminishing was still pretty new at the time, so it was a big deal that these guys came in and mowed down everyone. They simply felt like the most dangerous weapons in their respective playoffs. Miller missed one game (and indeed, two of the three runs Miller gave up in that 2016 postseason came in the Cubs’ Game 7 triumph), but Davis is forever etched in Kansas City baseball history.

Ashby may already be there for the Brewers; even if things don’t go particularly as planned in the World Series, few will forget his exploits in the first two rounds. But for a guy who, like Miller and Davis, didn’t function as a starter, and for a guy who hadn’t had a good postseason career before this season (in 10 appearances over three seasons, he had a 7.71 ERA in 9 1/3 innings and as many walks as strikeouts), Ashby has written himself into the Milwaukee record books. If he can continue in the World Series, he might just join a truly elite list of postseason relief runs the likes of which have only been seen a handful of times.