Kemp Alderman off to hot start thanks to batting stance adjustments, added speed

Prior to the Double-A season beginning, Miami Marlins outfield prospect Kemp Alderman told reporters that he wanted to have a 20/20 season (20 home runs, 20 stolen bases). That seemed to be an unlikely goal for a player who had only nine homers and nine steals over the previous two minor league seasons combined.

Through nine games, Alderman is well ahead of that pace, slashing .375/.432/.750/1.182 with three home runs, 11 RBI and five stolen bases. That earned him a selection to MLB Pipeline's Prospect Team of the Week.

Miami's second-round draft pick in 2023, Alderman missed nearly half of the 2024 season due to a hand injury. He reached the AA level for the first time in September, but slashed .174/.174/.348/.522 with one home run and three RBI through six games played. Fish On First spoke to Alderman about his limited experience in Pensacola and he said it "opened my eyes a lot."

"As you go up in the levels, you learn that you're not just up there swinging—you have to have a plan," said Alderman. "Just having my plan, my approach, sticking to it, and if it works, it works and if it doesn't, we'll go from there."

To make up for lost time, Alderman went to the Arizona Fall League. His plus power was on display during a phenomenal nine-game stretch where he slashed .306/.375/.833/1.208 with six home runs and eight RBI.

"It's a great experience," said Alderman. "Just getting to play with different guys, different orgs and see what they do, see what worked for them. Just playing against some really great competition, facing good arms...It was probably the most fun I've ever had playing the game of baseball, to be honest."

Alderman lost some weight entering 2025 to prove himself as "a big guy who can run," but another development has been his all-around improvement as a hitter. Carrying over from the AFL, the 22-year-old has switched to a new batting stance, holding his hands higher and his bat at a more horizontal angle.

The clip below shows Alderman's September 2024 stance on the left and his current stance on the right.

 

In these photos, you can more clearly see that his hands were previously at the letters as the pitcher began their delivery. They are now above his shoulders.

Swinging down at the ball has understandably caused his groundball percentage to spike up (from 49.0% to 58.3%), but the production doesn't lie. He is hitting for average and getting on base a lot more.

Alderman is a strong candidate to be added to the FOF Top 30 list following our next update.

Interested in learning more about the Miami Marlins' top prospects? Check out our comprehensive top prospects list that includes up-to-date stats, articles and videos about every prospect, scouting reports, and more!