Three American League hitters due for regression in 2024

Sometimes a hitter will throw up numbers that are at odds with what they normally produce. Some call it a career year or maybe everything just went right. In most cases, there are usually underlying reasons for the significant improvement. 

Here are three hitters in the American League who posted strong numbers in 2023, but will most likely regress back to their normal career production levels this coming season. Temper your expectations for 2024 based on last year's numbers. 

No. 3: Brent Rooker, OF, Athletics

Rooker kicked around the Majors following his debut in 2020 before landing in Oakland in 2023 – his fourth team in as many seasons. He had never shown much in his career, having produced a negative WAR. In 2023, though, Rooker exploded, pounding out 30 home runs while batting .246, well above his career average of .200 he had worked to prior to last season. 

There are plenty of indications that Rooker could slip back to previous production, but one telltale sign is his Batting Average on Balls in Play. In his first three seasons, covering 240 at bats, the outfielder's BABIP was .264, noticeably under the historical league mark of .300. In 2024, Rooker's BABIP was .317. 

Combine this with the fact he set a career-high in Fly Ball Rate (47.1 percent) and a career-low Ground Ball Rate (33.6 percent) – which is backward of you would expect for putting up a higher than normal BABIP. It's easier for ground balls to sneak through for hits than fly balls, meaning that there is a good chance Rooker's average will drop significantly in 2024. His power may be for real, now that he has earned regular playing time, but don't count on a .246 average again. 

No. 2: Austin Hays, OF, Orioles

Hays' BABIP for his career prior to 2023 was .292. Last year, it skyrocketed to .345, jumping his average from .257 for his career to .275 last season. Hays saw a big drop in his Line Drive Rate, from 19.2 percent to 16.9 percent, with almost no change in his Ground Ball Rate. Those numbers would indicate he had some really good luck on his batted balls. 

Another reason his 2024 might not be as rosy as 2023 is that Hays' outstanding first half inflated his final numbers. His first half BABIP was .389, but it was just under his normal numbers in that category in the second half. 

Don't be fooled by Hays overall numbers in 2023. He's probably still the same hitter he had been throughout his career before taking last year's statistical jump.

No. 1: Yandy Diaz, 1B, Rays

Diaz has always handled the bat pretty well, wracking up a solid .278 BA in his six-year career. It was something altogether different in 2023, when he led the league in hitting with an average of .330. BABIP indicates he was extremely lucky on batted balls as he posted a .367 mark in that stat, 54 points over his career numbers. 

His ground ball, fly ball and line drive rates were all right in line with his career numbers, though his Hard Hit Rate was a bit higher. Still, that was not enough to explain the huge jump on the success of his balls in play. 

DIaz is 32 this year and doesn't rely on power. He can still a productive hitter. Just don't expect anything near that .330 batting average again.