Hitting a baseball is one of the hardest things to do in sports, and in some cases, a minor adjustment such as losing the “feel” of the barrel or getting “on top” of the ball too much can create a significant regression in performance from one season to the next. Three offensive players that have underperformed relative to expectations this season have been Corbin Carroll, Julio Rodríguez, and Bo Bichette. All three players have seen regressions in power output this season, and their respective teams are counting on them to experience resurgences in the second half in order to reach their pre-season expectations. With the 2024 Major League Baseball season nearly halfway complete, most peripheral statistics have stabilized to a point where a reliable prognosis can be made as to why a given hitter has under or overperforming relative to expectations. This article will aim to identify the adjustments that Carroll, Rodríguez, and Bichette will need to make to their offensive approaches to get back on track in the second half of the season.
Since making his Major League debut at the end of the 2022 season, Corbin Carroll has emerged as a foundational player for the Arizona Diamondbacks, winning the 2023 NL Rookie of the Year en route to leading the team to their first World Series appearance since 2001. Known for his power-speed combination that turned him into a star last season, Carroll has experienced significant regression in power output during the first half of the 2024 season, resulting in him producing a wRC+ that is below league average so far this season.
As shown by the table above, Carroll has experienced a significant regression in his power output as indicated by the decrease in his isolated power and slugging percentage so far this season. After hitting 25 home runs en route to a Top 5 NL MVP finish last season, Carroll has only hit 2 home runs in 2024. On the bright side, Carroll has improved his plate discipline and lowered his strikeout rate this season which could provide him with a higher offensive floor if he can regain his ability to hit for power.
Why has Carroll seen such a dramatic reduction in power output in the first half? Taking a look at his batted ball metrics, it appears that Carroll has not been hitting the ball as hard and pulling the ball in the air as frequently as he was in 2023, which has resulted in him producing contact that is not ideal for tapping into his in-game power.
As shown by the table above, Carroll’s hard hit rate has decreased from 40.9% to 35.2% and his barrel rate has decreased from 7.6% to 4.3% in 2024, indicating that he has been making less hard contact at ideal launch angles this season. Carroll’s pulled fly ball rate has decreased to 2.2%, while his max. exit velocity is over 2 MPH lower than last season’s.
One reason for Carroll’s hard-hit regression could be due to the longstanding effects of the shoulder injury he experienced last season. Nagging effects from injuries of this nature can cause longstanding hard-hit issues with Major League hitters, with Cody Bellinger being a prime example of this phenomenon (Bellinger has not hit a ball over 110 mph exit velocity since his shoulder injury in the 2020 NLCS). It is possible that Carroll could have issues hitting the ball as hard as he did in the first half of the 2023 season for the foreseeable future due to the longstanding effects of this injury.
Another reason for Carroll’s power regression so far this season has been due to a change in his swing mechanics. As explained by Aram Leighton in a recent article for Just Baseball, Carroll has exhibited a much longer stride length this season which has caused his upper and lower body to become out of sync with each other as his weight is shifting well before his hands are ready to launch. This has resulted in Carroll’s swing path becoming much flatter, with his vertical bat angle decreasing from 26.5 degrees to 21.1 degrees according to data from SwingGraphs. A flatter bat angle results in fewer opportunities to make contact at an ideal launch angle conducive to power output, explaining the decrease in barrel rate that Carroll has experienced so far this season.
Personally, I am bearish on Carroll’s ability to regain his prior power output in the second half of the season. Swing changes are difficult to make, especially in-season, and it appears that a swing change is necessary in order for him to improve his offensive production. It is certainly within the realm of possibility that Carroll will be able to hit 25 home runs in a season again in the future, but it will require some significant adjustments in order for him to fully reach his offensive potential.
Since making his Major League debut at the start of the 2022 season, Julio Rodríguez has been one of the most electrifying players in all of Major League Baseball. His combination of plus defense and offensive production has turned him into one of the brightest stars in the game and the Seattle Mariners franchise cornerstone. While the Mariners currently lead the AL West courtesy of their outstanding pitching staff, Rodríguez has struggled offensively in the first half of 2024, producing a wRC+ of 89 so far this season.
As shown by the table above, Rodríguez’s decline in offensive production has been largely driven by his decreased power output this season, with his isolated power decreasing from .209 and .085 and his slugging percentage decreasing from .485 to .339. While his strikeout rate has seen a slight increase thus far, Rodríguez has maintained a walk rate that is close to his career average and his .339 BABIP is in line with the BABIPs he has produced throughout his career.
As shown by the table above, Rodríguez is still hitting the ball hard in 2024, producing a hard hit rate of 49.3% with a max. exit velocity of 114.5 so far this season. Rodríguez’s barrel rate has decreased from 11.9% to 8.9% so far this season, and this is likely due to a slight increase in ground ball rate, from 47.6% in 2023 to 48.4% in 2024. Rodríguez’s pulled fly ball rate has also decreased from 6.4% to 5.4%, and this is likely the main reason why he has not been able to hit for as much power in the first half.
Rodríguez has also shown an inability to generate offensive production over the heart of the plate this season, with heatmaps showing him generating most of his production on the inner third. Rodríguez had difficulty hitting pitches on the inner third of the plate last season, however, it appears that the decision he has made to improve his ability to cover pitches in this part of the zone has resulted in an unfavorable trade-off of less power production. Perhaps this can be resolved by him resetting his offensive approach at the plate and focusing on creating damage on pitches over the heart of the plate, and the All-Star Break might be the perfect opportunity for him to reset his approach.
There has been a notion throughout Rodríguez’s career that he is more of a “second-half player” than a “first-half player”, so I decided to look at his seasonal splits to see if there was any truth to this notion. Evidently, Rodríguez has been a much better hitter in the second-half of the season over the past two seasons, posting a 160 wRC+ in the second half compared to a 119 wRC+ in the first half. It should be noted that first-half/second-half splits are almost always more noise than signal, however, it is an interesting trend that has occurred throughout Rodríguez’s young career and could be an indication that more production is on the way in the second half of the season.
The Mariners have been off to a solid start to the 2024 season, and Rodríguez’s plus defensive ability in center field provides him with a solid floor that allows him to produce even when he is going through an offensive slump. If he can regain his ability to generate offensive production on pitches over the heart of the plate and pull more fly balls for power, then Rodríguez may experience another second-half resurgence this season and once again lead the Mariners to the postseason.
Upon making his Major League debut in the middle of the 2019 season, Bo Bichette was projected to be the Blue Jays shortstop of the future and expected to headline a young core alongside Vladimir Guerrero Jr. that would turn Toronto into a perennial contender. While Bichette has produced a 4-win season in each of the past three seasons, the Blue Jays have often fallen short of the lofty expectations put upon them and this season has been no different, with the team currently last place in the AL East. While Bichette has always been above league-average offensively over the course of his career, his offensive production has sharply declined so far this season, raising questions about his long-term offensive outlook.
As shown by the table above, Bichette has seen a significant decline in offensive production so far this season, with his wRC+ declining from 125 to 78. Similar to Carroll and Rodríguez, most of this decline can be attributed to a regression in power output as Bichette’s isolated power has declined from .168 to .103, and his slugging percentage has declined from .475 to .337. Some of the decline can also be attributed to a .269 BABIP, which is due to experience some positive regression over the remainder of the season as Bichette has consistently maintained high BABIPs throughout his career.
Bichette has continued to hit the ball hard this season, with a 44% hard-hit rate so far this season, however, his barrel rate has decreased from 9.6% to 4.6% this season which indicates that he has not been frequently hitting hard-hit balls at ideal launch angles during the first half of the season. Since making his Major League debut, Bichette has been known as a player who can hit the ball to all fields, and this year his pull rate has declined to 26.9%. While letting the ball travel and spraying the ball to all fields is a good strategy to generate more contact, this approach places a ceiling on the amount of power a hitter is able to generate, as hitting for power to the opposite field requires higher exit velocities than pull-side power.
For these reasons, I believe that Bichette’s increasing tendency to hit the ball to the opposite field is placing a limit on the amount of power he is able to generate. This focus has allowed him to hit for more contact, as his 9.9% swinging strike rate this season is a career-low, but it has come at the unfavorable trade-off of hitting for less power. Bichette has utilized an all-fields approach over the entirety of his career, so it will be difficult to make an adjustment in this area, but he needs to place a focus on pulling the ball in the air to tap into more power in-game and improve his level of offensive production. Even just increasing his pull rate to 30% could make a big difference in his power output.
Bichette also has an aggressive approach at the plate, with his 57.9% swing rate this season being the highest of his career. While he has shown an ability to hit for contact with such a high swing rate, it raises some questions about how well his offensive profile will age once he loses some of his contact ability in his 30s. Bichette is still only 26 years old, so perhaps this is not an issue in the short term, but it does create some pessimism when evaluating his long-term profile. Perhaps becoming more selective with his swing decisions could cause Bichette to increase his power output as well, as he would be able to prioritize making contact on pitches that he can drive for power.
Overall, I have mixed feelings about Bichette’s long-term offensive profile. I do expect his BABIP to experience some positive regression which should raise his offensive production closer to league-average, however, his declining tendency to pull the ball raises some concerns over how much power he will be able to tap into in-game. I would expect him to finish the season closer to a 100 wRC+, with his long-term outlook being closer to an average to above-average bat rather than a 5-win player unless he makes an adjustment to his batted ball profile.
Concluding Thoughts
With the 2024 Major League Baseball season nearly halfway complete, most peripheral statistics have stabilized to a point where a reliable prognosis can be made as to why a given hitter has under or overperforming relative to expectations. 162 games makes for a long season, and even the smallest adjustments can add up and make a big difference in impacting a player’s offensive production over the course of a full season. I will be keeping an eye on the adjustments that Corbin Carroll, Julio Rodríguez, and Bo Bichette make in the second half of the season to improve their offensive production.
Photos courtesy of Icon Sportswire | Adapted by Aaron Polcare (@bearydoesgfx on X)