Cody Bellinger's struggles against these two pitches killed his 2024 numbers

Expected to be the middle-of-the-order weapon he proved to be in 2023, Cody Bellinger turned in a solid performance this year - but came nowhere near reaching, let alone exceeding, the expectations the Chicago Cubs or their fanbase had for him.

He was slightly better than the league average in terms of both wRc+ (109) and OPS+ (111) and provided Craig Counsell a ton of versatility, seeing time at first base, as well as in center and right field, but for $27.5 million, the team needed him to be a run producer and the slug in his game saw major regression from the year prior.

Looking at most metrics, the downturn in offensive production is tough to explain. His barrel rate was slightly up, average and max exit velocities almost exactly what they were in 2023 and the same story with his walk and strikeout rates. Digging a little deeper though, two pitches really gave him headaches this season.

In his first year with the Cubs, Bellinger destroyed change-ups. In fact, according to Baseball Savant's Run Value metric, he's only been better against a specific pitch in his career twice - once in 2018 and once in 2019, when he was an All-Star, won a Silver slugger and earned National League MVP honors.

This year, though, was a very different story. He went from a +12 Run Value in 2023 to a +3 this year. His batting average against change-ups fell from .446 to .294 and his power dropped sharply, as well, evidenced by a slugging percentage that went from .677 to .471.

Again, not terrible numbers by any stretch, but it's clear his power numbers in 2023 were driven, at least in part, by some unsustainable success against this pitch. It was a similar story against sliders: Bellinger batted .179 and slugged just .254 after hanging a .367 average and .617 slugging percentage on them the prior year.

Looking at breaking and offspeed pitches, in general, Bellinger's slugging percentage fell more than 200 points this year on each. He more or less maintained his slug against the fastball - but he failed to adjust off the heater and the numbers lay that out pretty clearly. Sure, he had some home/road splits in there, thanks to Wrigley Field's pitcher-friendly atmosphere this season, but that wasn't what killed him. If he opts out next month, it's up to Scott Boras to convince prospective suitors otherwise.