10 hitters who have improved the most since the All-Star break

August 22nd, 2023

Even this late in the year, there’s still time for players to completely change the tenor of their seasons.

Take the hitters below for example. Thanks to big second-half performances, their numbers look a lot better now than they did just one month ago.

In fact, no hitter (min. 350 plate appearances in 2023) has added more points to his seasonal OPS since the All-Star break than these 10.

All stats below are through Sunday.

1. , Orioles: +112 points
Anyone who followed Mountcastle’s numbers closely in the first half might have seen this surge coming. The O’s slugger was among the unluckiest hitters in baseball during that time, with a difference of 37 points between his batting average (.230) and expected BA (.267) and a difference of 107 points between his slugging percentage (.424) and expected SLG (.531). His fortunes have turned in the second half, during which he has slashed .377/.438/.613 with six homers over 32 games to raise his OPS from .691 to .803.

2. , Red Sox: +108 points
The 26th overall pick in the 2018 Draft, Casas opened this season as Boston’s unquestioned starter at first base after showing promise in an abbreviated stint with the team in 2022. The Red Sox stuck with him even as he struggled to the tune of a .184/.300/.342 slash with six homers over his first 49 games in 2023, and their faith in the youngster has been rewarded. Casas ended the first half with a .727 OPS, but he’s up to .836 on the year thanks to a 1.109 OPS with 11 homers since the All-Star break.

3-T. , Cardinals: +95 points
Although Nootbaar has missed a lot of time due to injuries -- he’s currently on the IL for the third time this season -- his production has been one of the few bright spots for St. Louis in 2023. The outfielder leads the team with an .835 OPS, up from .740 at the break. Nootbaar has notched a .330 average with seven homers and a 1.027 OPS in the second half to turn his season around.

3-T. , Nationals: +95 points
After putting up a .673 OPS in his first full season with Washington, Ruiz mustered just a .226/.279/.360 slash in the first half of 2023. But since the break, the 25-year-old has looked every bit like the franchise catcher the Nats hoped he’d become when they acquired him from the Dodgers as part of the trade return for Trea Turner and Max Scherzer in 2021. Ruiz has recorded a .336/.402/.566 line with six homers and more walks (12) than strikeouts (11) in the second half, raising his overall OPS to .734.

5-T. , Cubs: +87 points
What was already shaping up to be a strong bounceback season for the 2019 NL MVP has gotten even better since the All-Star break. After hitting .298 with nine homers and an .846 OPS in the first half, Bellinger has gone deep 11 times in the second half while slashing .367/.401/.680. His overall .933 OPS is a 322-point improvement from his .611 OPS across 2021-22.

5-T. , Twins: +87 points
Kepler looked like a foundational piece for the Twins when he posted 36 homers and an .855 OPS in 2019, but he followed that up with a .707 OPS from 2020-22. It was more of the same in the first half of 2023, with Kepler recording a .688 OPS. However, he’s been closer to his 2019 self since the break, hitting .299 with eight homers and a .928 OPS over 32 games. His OPS has climbed to .775 on the year. If he keeps it up, his 2024 club option ($10 million with a $1 million buyout) will become a much tougher call for the Twins this offseason.

7. Bobby Witt Jr., Royals: +78 points
As MLB.com’s David Adler recently noted, Witt’s breakout might have started much earlier this season if not for some poor luck. In any case, it’s happening now, with the former highly touted prospect recording a .343/.374/.650 slash with 10 homers, 32 RBIs and 10 steals since the All-Star break. His overall OPS has jumped to .820, up from .722 in his rookie year and .742 in the first half of 2023.

8. , Mariners: +77 points
Though Rodríguez made the 2023 AL All-Star team and put on a show in front of his hometown fans at the Home Run Derby in Seattle, his first-half performance (.721 OPS) -- as well as the Mariners’ 45-44 record -- left a lot to be desired. However, Rodríguez has hit .347 with eight homers, 12 doubles, 30 RBIs and a .986 OPS since the break, fueling Seattle’s surge back into playoff contention. The 22-year-old’s hot streak reached historic levels this past week, when he broke the AL/NL record for the most hits in a four-game span with 17.

9. , Royals: +73 points
Despite some promising quality of contact metrics -- he ranks in the 97th percentile in average exit velocity and the 93rd percentile in hard-hit rate -- Melendez had a tough first half (.622 OPS). He has shown improvement lately, though, producing a .302 average, six homers and an .870 OPS since the All-Star break to increase his overall OPS to .695.

10. , Braves: +72 points
Riley earned his second straight All-Star selection in 2023, but his .775 OPS at the break was a far cry from the .878 OPS he posted in 2022. He’s much closer to last year’s mark now, increasing his overall OPS to .847 amid an incredible post-break performance -- 13 homers, 33 RBIs and a .312/.366/.667 slash in 34 games.