Last week, we looked at fly ball pitchers and how they’ve fared in air ball out rate. Dylan Cease, who has some of the best peripherals and underlying metrics of his career, was among the pitchers featured in the piece as a regressor in air ball out rate and is part of the explanation for his ERA being ballooned to 4.79, the second worst of his career. Jack Flaherty was the other pitcher in the worse ERA category, as his fly ball rate spiked to a career high. Both pitchers are among the top increasers in BABIP from 2024 to 2025, and that will be a common theme for pitchers discussed here for groundball out rate.
On the opposite end, lefty fly ball pitchers Shota Imanaga and Andrew Abbott have had strong campaigns and are both in the top 20 for year-to-year improvers in air ball out rate, and have perhaps established the ability to induce weaker contact through the air.
Today, we’ll look at the ground ball out rate for pitchers with varying success levels. Groundballs are the better outcome for pitchers, and we like to see higher ground ball rates. But like with any ball in play, pitchers are dependent on their defense to complete the out.
Looking at groundball out rates at the team and pitcher level offers some insight into why a few pitchers’ seasons have taken the turns they have. We’ll take a slightly different approach to the last piece, looking into two of the top risers and two of the biggest fallers in groundball out rate. Here are the top 25 improvers from 2024 to 2025:
And the bottom 25:
Bassitt has been an integral piece to a Blue Jays team that is tied for the most wins in baseball. He holds a 4.24 ERA, 1.34 WHIP, and a 17.1% K-BB%. The ERA and WHIP marks aren’t much to write home about, but the K-BB% is the second-best mark of his career. The pitch mix has expanded to a whopping eight pitches, and he’s always produced a healthy amount of ground balls.
His groundball out rate was roughly seven percentage points below the 73.3% league average, which put him in the bottom 15 of all pitchers (min. 100 groundballs). He’s among the top 10 increasers from year to year, and is at 75.6% in 2025. The Blue Jays have converted grounders into outs at about the same rate in the past two years (73.3% in 2024, 73.6% in 2025). But Bassitt’s groundball out rate in 2024 was significantly lower than that of his Blue Jays teammates. The next closest was Chad Green at 70.9%, highlighting the wide gap between Bassitt and the rest of the staff.
It’s not as if Bassitt was giving up a ton of hard contact on his grounders, as his average exit velocity against him on grounders was very similar to the others. And the Blue Jays have put an emphasis on defense the past few seasons, and they’ve been top five in each of the last two seasons in total infield Defensive Runs Saved.
The 36-year-old has also thrown his curveball at a career-high rate this season, and hitters are batting just .150 (12-for-80) on it with an 18.5% hard-hit rate, good for third best in baseball among all curveballs. It is interesting, however, that his BABIP is almost unchanged. After a five-year run from 2019 to 2023, during which his BABIP did not deviate significantly, ranging from .267 to .282, it has spiked to .333 and .331 over the past two seasons. Despite that, Bassitt continues to be one of the league’s inning eaters and one of the premier kitchen sink guys with good command.
Holmes swapped New York teams over the off-season and continues a trend of relievers turned starters. The strikeout rate has fallen meaningfully as he’s lost some stuff in the transition (25.1% to 18.4%), as well as the groundball rate (65% to 55.8%). But he’s also near the top of improvers in out rate on grounders switching from the Mets to Yankees, from 68.1% to a solidly above average 76.3%.
Holmes has one of the more unique characteristics for a pitcher, with a higher arm angle (44 degrees), but also some of the most drop on his sinker in the league. It is movement that hitters don’t expect, given his arm slot, and what makes him a success.
The 32-year-old has allowed harder contact on average on grounders this year compared to last year, but has improved in results regardless. He has the ninth biggest reduction in BABIP from 2024 to 2025 of all pitchers (min. 60 innings both seasons).
Before Holmes’ arrival, the Mets were sixth in this metric last season and have dropped to 22nd this season. Their infield, excluding catcher, is 19th in the majors with -3 DRS. Comparatively, they were a positive 7 last season.
It’s been a nightmare season for Ober, as he’s posted a career-worst 5.28 ERA, 1.41 WHIP, and 12.8% K-BB% in 92 innings in 2025. Home runs have always been an issue for him as he doesn’t throw hard, but his 2.05 HR/9 is second-worst among starters.
Ober certainly fits the profile of a fly ball pitcher with a career 49.8% fly ball rate, but he saw the steepest drop in groundball out rate from 2024 to 2025 by a wide margin. The Twins’ defense has been the worst in baseball at converting grounders into outs this season at 69.3%. His teammate Joe Ryan is the third biggest dropper as well, who is having a stellar season regardless. The 6’9″ righty relies on his elite extension to allow his below-average stuff to play up, but the velocity is down more than a tick this season to 90.6 MPH.
It is meaningful that he is giving up much harder contact on grounders compared to last year. When he did generate a groundball, which wasn’t too often, his 81.7 MPH average exit velocity ranked eighth lowest out of 382 pitchers (min. 50 PA). This season, it’s jumped to a more mediocre 86.3 MPH average exit velocity. And when combined with one of the worst infield defenses, it doesn’t make for positive results usually. On top of that, his out rate on balls in the air has also fallen over three percentage points.
Another reason for Ober’s falloff is his inability to put batters away. All of his pitches except for his sweeper have a lower PutAway% this season. The track record is solid enough for the 30-year-old to bounce back, but the declining velocity and lack of stuff are a worry.
Soriano is a pitcher I was bought in before the season, and there have been plenty of highs and lows. He is tied for fourth among starters with six starts of at least six shutout innings this year, only behind Tarik Skubal, Yoshinobu Yamamoto, and Carlos Rodon. But there are still moments of inconsistency, especially with his control. He leads the majors with 12 outings allowing at least three walks.
The stuff is so tantalizing with the 26-year-old, however. And there have been legitimate strides in his command and in generating swing and miss. His 110 Location+ is tied for 10th best among all starters, with command artists like Paul Skenes, Bryan Woo, and Logan Webb. His 67.5% groundball rate is easily the highest in the league, with Andre Pallante in second at 61.5%. And his nasty secondary offerings have led to an increase in swinging strike rate to 11.5%. Those numbers are right in line with prime Framber Valdez.
His heavy amount of grounders hasn’t yielded the same out rate in 2025, as he is tied for the 10th biggest drop. The Angels collectively have been a below-average defensive unit, and are 25th in groundball out rate at 71.4%. Like Ober, Soriano has been affected by his balls in the air as well. He has just a 55% out rate on balls in the air this season, well below the 67.9% league average, and ranks 311th out of 316 pitchers.
The groundball maestro does concede plenty of hard contact when it’s put in play. His 94.9 MPH exit velocity on air balls is tied for fifth highest, and his 89.7 MOH average exit velocity on grounders is tied for 19th highest out of 356 pitchers. These factors have all contributed to one of the highest year-to-year increases in BABIP as well, which has been a common thread amongst most pitchers discussed.
