This offseason, the Marlins upgraded their sluggish offense by signing Jorge Soler and Avisail Garcia and trading for catcher Jacob Stallings and infielder Joey Wendle. After finishing second-to-last in runs in 2021, Miami dreamed of pairing an above-average lineup with its already-dominant starting rotation. But so far this year, it isn’t Miami’s new additions driving the team’s solid offense (104 wRC+). Jazz Chisholm Jr. , the Marlins' electrifying second baseman and leadoff hitter, is enjoying a breakout season and powering a much-improved Miami lineup.

In 124 games as a rookie last year, Chisholm slashed .248/.303/.425, with a decent 42% hard-hit and 9% barrel rate. But this year, the eccentric 24-year-old has emerged as one of the best young players in baseball. Through Wednesday, when Chisholm hit a leadoff triple and homered in the fifth inning versus the Nationals, he was hitting .304 with a .346 on-base percentage and slugging .617 in 128 plate appearances this season.

He’s leading the Marlins with seven home runs, six stolen bases, 27 RBIs and a .963 OPS. He also already has seven doubles and four triples, placing him well on his way to exceeding his totals from last year. Chisholm, already one of the most charismatic personalities in baseball, is becoming a star before our eyes. Let’s dig into how and why.

Lift and pull

Chisholm’s rookie year was plagued with an excessive amount of ground balls. He put the ball on the ground in nearly half of his balls in play (49.4%). With his 94th-percentile sprint speed, Chisholm’s 2021 batted-ball profile led to 24 infield hits, but it didn’t help his power numbers. He ended the season with just 42 extra-base hits in 507 plate appearances.

This year, Chisholm is hitting the ball on the ground just 37.2% of the time, adding in more fly balls (31.4%) and line drives (26.7%). His average launch angle jumped from 9 degrees last year to 15.7 this year, which is among the biggest leaps in baseball.

That’s not the only change to his batted ball profile. After spraying the ball all over the field last season, Chisholm is hitting it to the pull side nearly as much as anyone in baseball. His 50% pull percentage ranks seventh in baseball among qualifiers.

And he’s crushing the ball when he’s doing it. Chisholm is hitting .525 with seven doubles, three triples, and three home runs to the pull side so far this year.

While three of his home runs this year have gone to the opposite field, pull-side power is important for Chisholm moving forward. At 5-foot-11, 184 pounds, Chisholm may not be able to consistently hit the ball out to all fields à la Giancarlo Stanton or Aaron Judge. A home run profile similar to Francisco Lindor or Jose Ramirez from the left side, taking advantage of short right-field porches, is how Chisholm can reach the 30-40 home run threshold at his size.

Do more with less

Though the second baseman’s average exit velocity has gone up half a tick (90.7 mph from 90.2 mph), it’s his hard hit and barrel rate that uncover his breakout.

His barrel rate has jumped 6.9 percentage points to 14%, which is among the largest jumps in baseball. He’s hitting the ball hard nearly half the time (46.5%), which is a significant improvement on his 2021 season when he had a hard-hit rate of 42%. In other words, he's hitting the ball hard more consistently and doing so in the right direction.

How is he doing it? Trying less.

“I haven’t been swinging as hard as I was last year,” Chisholm told MLB.com Marlins beat reporter Christina DeNicola. “I’m trying to be more controlled at the plate instead of just trying to launch everything, even though that’s what's still happening. But I’m trying to be more controlled and consistent.”

Crush the slow stuff

For the first time in his young career, Chisholm is crushing the slow stuff.

After batting .202/.240/.349 in 139 at-bats against breaking balls and offspeed pitches last year with similar expected stats, Chisholm is batting .350/.354/.707 in 62 plate appearances ending on breaking and offspeed pitches this year.

He’s already matched his home run total against breaking balls from last year (four). Chisholm’s 15 hits against breaking balls rank seventh in baseball this year. He’s only had four hits against offspeed pitches this year, but he’s seeing them much less than he’s seeing breaking balls (28.8% of pitches vs. 19.2%).

Chisholm’s confidence in hitting fastballs, (.818 OPS vs. fastballs for his career, including a home run off a 100 mph Jacob deGrom heater last year), has allowed him to be better prepared for pitchers’ breaking and offspeed pitches, he said.

“I know a lot of guys can’t beat me with their fastballs,” Chisholm said. “The hardest pitches to hit in baseball are sliders, curveballs, offspeed. I’d rather be on for [breaking and offspeed pitches] than a fastball because I can always react to a fastball. I’m going to be prepared to hit everyone's offspeed pitches because I know I can hit their fastball.”

It looks like Chisholm’s raw power and speed tools are coming together. In Chisholm, the Marlins have a star to build their lineup around moving forward as they look to make the playoffs for just the second time since 2003. They already have a playoff-worthy pitching staff, but now, they have a star middle infielder to drive their offense.