The 2024 Marlins rotation and the left-handed quandary

The initial 2024 Miami Marlins starting rotation is set. Left-handers Jesús Luzardo, A.J. Puk, Ryan Weathers and Trevor Rogers all made the cut. At least for the early portion of the regular season, that means their rotation will be more southpaw-reliant than any other in Marlins history. Max Meyer will be the fifth starter, making him the only right-handed pitcher in the rotation.

The MLB record for most starts by left-handed pitchers in a season is 127, set by the 1983 New York Yankees. Though unlikely the Marlins will match or best this mark, should starters Edward Cabrera (shoulder) and Eury Pérez (elbow) miss extended time, Miami could find themselves trotting out lefties far more than they're accustomed to. It's worth noting, too, the absence of another left-handed starter, Braxton Garrett, who will miss the start of the season due to shoulder soreness, but is on track to reclaim his major league rotation spot by the end of April. 

In what may best be described as baseball's "golden age" of analytics, utilizing a rotation of primarily same-handed hurlers goes against the grain of confronting hitters with "different looks" on the mound. History has shown that teams who do so in this fashion have managed to remain quite successful.

Of the 27 teams since the start of the modern era (1901) to have at least 100 of their games started by left-handers, 18 of them have finished at or above .500. Five of those teams ('65 Dodgers, '73 Mets, '91 Braves, '17 Dodgers and '18 Red Sox) went to the World Series, with an additional five making postseason appearances. These teams played to a collective .532 winning percentage record. For comparison's sake, that's akin to the 2022 Philadelphia Phillies (86-76), who would go on to appear in that year's World Series

Even for some of those clubs who failed to play October baseball, their rotations were effective despite frequently dealing with a platoon disadvantage.

The 2015 Chicago White Sox boasted a left-handed heavy rotation that included the likes of Chris Sale, Carlos Rodón, José Quintana, and John Danks, for a South Sider's club that went 76-86, merely good enough for fourth in the American League Central. Though the pitching staff's collective 3.98 ERA ranked 14th, the club's southpaws—who accounted for 116 of the team's 162 games started—posted a far more encouraging 3.78 ERA, which would've ranked 11th in the Majors. Their 13 fWAR from lefties was 2.5 wins better than any other club.

"So you're telling me there's a chance?" Yes, Lloyd, but the current-look Marlins rotation comes with numerous questions and concerns that may override the obvious talent of its members.

For A.J. Puk, 2024 represents his first go-around as a starter at the big league level after spending parts of his first four seasons in the bullpen. Primarily a starter during his time at the University of Florida, Puk's last extensive work as a starter came when he made 24 starts for Oakland's High-A and Double-A affiliates in 2017.

Beyond being limited to merely 18 innings in 2023, Trevor Rogers' effectiveness is in serious doubt. The former All-Star boasts a 5.26 ERA (4.32 FIP) in 27 starts since the 2022 season, and Rogers' fastball velocity has not yet been restored to his pre-injury norm.

Despite an encouraging spring, the return on Ryan Weathers' early big league career has been anything but, as evidenced by a 5.88 ERA and 1.53 WHIP across parts of three seasons. Former first-round pick Max Meyer hasn't pitched since July 2022 after undergoing Tommy John surgery and the Marlins had every intention of sending him down to the minors for further refinement prior to Eury Pérez's elbow issue. 

Luzardo, undoubtedly the safest of the bunch, does not find himself immune to skepticism, either. His .616 opponent OPS when facing hitters the first time jumps to .727 when facing a second time, and .855 when seeing them for a third time, a mark which ranked 41st of the 46 starters to face at least 150 hitters in said spots. The Marlins will be counting on him to sustain his success deeper into his starts while also duplicating his 2023 feat of making every scheduled appearance.