Andrew Heaney's brilliance has been Pirates coaching staff's best work yet

The Pittsburgh Pirates needed to make multiple key additions in order to improve upon back-to-back 76-win seasons. While the club ideally would have added more to the lineup or bullpen, the Pirates made one of the league's most impactful additions to date in starting pitcher Andrew Heaney.

After entering the winter likely expecting a multi-year deal, the left-hander found himself still on the free agent market in late February, prompting the Pirates to pounce. Heaney signed for just $5.25 million as the Bucs continued their annual tradition of adding veteran southpaws to PNC Park.

That decision has panned out better than anyone anticipated, as Heaney has been one of MLB's best pitchers to this point in the young season. Among all qualified National League pitchers, Heaney ranks fourth in ERA (1.72), first in WHIP (0.77), eighth in FIP (2.25), and sixth in bWAR (1.3). In addition, he's in the 99th percentile among all pitchers in Pitching Run Value (plus-10). That's Paul Skenes territory.

Andrew Heaney is playing the best baseball of his 12-year career with the Pittsburgh Pirates.

A couple of small tweaks have led to this substantial effectiveness, despite Heaney's unimposing fastball (averaging just 90.0 MPH this season). First, he's adjusted his pitch mix. He's cut the usage of his slider, formerly his go-to secondary offering, in half. He now throws his curveball (which Statcast actually classifies as two different pitches) as frequently as his slider, but he now leans on a devastating changeup that is nearly impossible for right-handed hitters to square up.

Diversifying and balancing the usage of his secondary pitches (he's thrown roughly 21% changeups, 13% sliders, and 13% curveballs) keeps hitters off balance and prevents them from sitting on his fastball, which is not thrown hard and has been left middle-middle more frequently than in years past. Despite unflattering metrics on his four-seam fastball, hitters are batting just .140 and slugging .209 against the pitch, which Heaney has used to record 14 of his 31 strikeouts (no other pitch has more than six).

Additionally, Heaney is throwing from a lower arm slot than before. Statcast has arm angle release data going back to 2020. He threw from a 30-degree angle last season and had bottomed out at 27 degrees in 2022, when he had a 3.10 ERA and 35.5% strikeout rate with the Dodgers.

This season, Heaney's average arm angle is 25 degrees, which has produced immediate results across the board—every single one of Heaney's pitches is averaging more horizontal movement compared to 2024. This has led to more strikeouts and, more importantly, a huge jump in groundball rate (seventh percentile in 2024 to 51st percentile in 2025).

Having Heaney make half of his starts at PNC Park was meant to minimize the damage on the many flyballs he allows. He's only made two starts in Pittsburgh so far, but he's gone at least seven innings in each, surrendered a total of one run, and hitters are just 1-for-12 with no home runs on flyballs at PNC Park. The lone homer he's allowed was in the notoriously small Great American Ball Park in Cincinnati, and has accounted for four of the six earned runs on Heaney's record.

He may wind up as trade bait come summer, but the improvements Heaney has made and the impact he's had on the 2025 Pirates cannot be understated. The Pirates' pitching lab has seen success with left-handed pitchers year after year, and Heaney has been the greatest bright spot of them all.