Hunter Greene will enter the 2024-2025 off-season after completing his most successful big-league campaign. The 24-year-old right-hander was selected to his first all-star team and currently has a 2.83 ERA. This is a strong improvement over his 4.62 career ERA going into 2024. Despite an elbow injury that has sidelined him for the last month, Greene has logged a career-high 143.1 innings pitched this season.
When Greene burst onto the scene in 2022, he instantly became known for his high-velocity fastball, easily hitting triple digits. That same 4-seamer was the catalyst behind Greene’s 2024 breakout.
From 2022 to 2023, Greene had the second-highest average 4-seam Fastball velocity among the 147 pitchers to throw at least 1,000 4-seamers between the two seasons. Greene’s fastball clocked in at an average of 98.6 mph. Despite this, the results didn’t follow.
In his first two MLB seasons, opponents batted .263 and slugged .516 with a wOBA of .378 in 578 plate appearances. Greene’s 4-seamer had a Run-Value against of -29 over those two seasons, tied for the 4th worst in the Majors. One of the hardest fastballs in the league was also one of the most hittable.
Turning a Corner
The results of Greene’s fastball dramatically changed for the better in 2024. Opposing hitters batted .186 against it and slugged .286. The expected statistics have also gone down with them. The expected batting average (xBA) on Greene’s fastballs this season is at .193, and the expected slugging (xSLG) is at .311. Among the 187 pitchers with at least 100 plate appearances ending on a 4-seamer this year, Greene ranks 22nd best in AVG against, tied for 7th best in SLG against, 12th best in xBA against, and 8th best in xSLG against. With these results and the volume of fastballs Greene has thrown this season, the Run-Value on his 4-Seamer has risen to +19, the 3rd highest among all 4-seamers and tied for 5th highest among all pitches in Major League Baseball.
To get these improved results, Greene saw a change in batted ball results against his 4-Seamer.
In 2024, all Major Leaguers are hitting .404 and slugging .803 on fly balls and line drives against 4-seam Fastballs. They are also hitting .232 and slugging .252 against ground balls and pop-ups against 4-seamers. From 2022-2023, The fly ball/line drive rate on Greene’s 4-seamer was 65.6%. In 2024, it has fallen to 57.6%, just below the Major League average of 57.9%. This change in batted ball results has allowed Greene to surrender a lower rate of more damaging contact.
Limiting the Damage
But even when Greene allowed fly balls against his fastball in 2024, he did a much better job of preventing the big hits.
From 2022-2023, opponents hit .300 and slugged .946 when hitting fly balls against Greene’s 4-seamer. Among the 42 pitchers to allow at least 100 fly balls on 4-seamers between the two years, his AVG against ranked 3rd worst, and his SLG against ranked 4th worst. In 2024, opponents hit just .103 and slugged just .294 when hitting fly balls against Greene’s 4-seamer. After allowing 29 home runs against his 4-seamer over the last two years, he has allowed just four this year.
This is because Greene is allowing weaker contact in the air. From 2022-2023, the barrel rate on fly balls against his 4-seamer was 23.7%. In 2024, it is just 9.9%, the 3rd lowest among the 155 pitchers with at least 25 fly balls against 4-seamers this season.
Also in Greene’s first two big league seasons, 22.9% of fly balls given up were hit to the pull side, the easiest way to convert fly balls into home runs. In 2024, just 14.1% of fly balls allowed by Greene have been pulled, the 4th lowest rate among the 47 pitchers with at least 50 batted balls allowed this year.
Greene has gotten opposing hitters to get further under the ball. Throughout the Major Leagues in 2024, fly balls against 4-seamers with a launch angle at or above 40° leave the park 1.3% of the time. From 2022-2023, 36.6% of fly balls hit against Greene’s 4-seamer have been hit at or above 40°. In 2024, that number is up to 54.9%, the 9th highest on the aforementioned list of 155.
These changes have caused the home run/fly ball rate on Greene’s 4-seamer to go from 19.1% before this year to 5.6% this year, the 11th lowest on the aforementioned list of 155.
What is Different?
It’s hard to pinpoint an exact reason Greene has seen these changes in results, but there have been some adjustments made in 2024 to his fastball and arsenal.
The horizontal movement on Greene’s 4-Seamer has appeared different in 2024.
Greene’s 4-seamer generated an average arm-side movement of 11.7 and 11.6 inches in 2022 and 2023 respectively. In 2024, it’ has generated’s generating only 8.9 inches of arm-side movement. This change could have led to the change Greene saw in his results.
In 2024, Major Leaguers are hitting .261 and slugging .466 on 4-Seamers with between 11-12 inches of arm-side movement with a home/fly ball rate of 17.9%. They are also hitting .237 and slugging .405 on 4-Seamers with a home run/fly ball rate of 13.5%.
Greene’s fastball changed in 2024 to be more in line with movement that better prevents base hits and home runs than its previous movement.
Greene also added a split-finger fastball to his arsenal in 2024. Greene has thrown this splitter 8.4% of the time, mostly to lefties. This has given hitters other pitches to consider when facing Greene.
Greene is working his way back to the Reds after his elbow injury. This year will be seen as his most successful season as a Major Leaguer whether or not he rejoins the team before the end of the regular season. His 4-seam Fastball underwent several changes which led to the improved results Greene saw in 2024.
Featured photo via @Reds twitter
All stats updated prior to play on 9/14
