NEWSLETTER
For as much as he’s carried the 2023 Chicago Cubs offense at times, it has been impossible to not notice Cody Bellinger’s recent struggles at the plate.
Since mid-August, Bellinger has been only about a league-average bat. Of note, David Ross said on September 4 that Bellinger was dealing with some “bumps and bruises” earlier this month, but he didn’t get any time off – just a couple games at DH. Since that date, Bellinger has hit just .235/.286/.392/82 wRC+. Then again, his barrel rate and hard hit rate are both up in that time, and he’s still not striking out. So I’m not really sure we can say he’s definitely worn down, even as much as it has FELT like that while watching him. Then again, a sharp uptick in his groundball rate – which has been the primary culprit in his down numbers – could be related to bat speed, which could be related to general tiredness.
But I’m actually not going to get into all that. There’s too much we don’t know about how a guy is feeling behind the scenes, and the sample is too small to extrapolate too much. All we know is that there were some “bumps and bruises” earlier this month, and Bellinger hasn’t really been hitting over the past month or so.
Could there be something else going on?
I ask, because Mike Petriello threaded up some thoughts on Cody Bellinger versus fastballs, and it caught my eye:
Then, in a mailbag at The Athletic today, Sahadev Sharma noted about Bellinger: “Pitchers have upped their fastball usage against him this month and it’s working, as he’s had his worst month against heaters (.172 wOBA).” Maybe that right there is a sign of wearing down? Not catching up to fastballs to do damage?
Well, that’s a mixed bag, too, when you dig in. Sorry if you’re looking for firm conclusions, because you won’t find them below.
For one quick thing, although Bellinger’s wOBA is way down on fastballs in September, his expected wOBA at Statcast (.265 – i.e., the measure of the actual quality of his contact) is roughly the same as August and June, for example, and is only a tick below his season mark (.305).
That xwOBA number is obviously still quite bad against fastballs, but we can break it down a little further by looking at pitch values on FanGraphs. There, Bellinger has been OK against non-cutter fastballs this year, so I suspect the inclusion of cutters in “fastballs” at Statcast is really dragging down the overall fastball numbers. So it might just be noise. All the September fastball stuff.
But Bellinger has, like Petriello said, WRECKED breaking and offspeed stuff this year. There probably is something there – throw him less breaking and offspeed stuff, and thus all that is left is an increase in fastballs – rather than a specific and new intention to throw him more fastballs because he’s suddenly struggling against fastballs. Given that his history looks like a mix of good and bad years against fastballs (all against the backdrop of the overall extremes in his performance that you are already well aware of), there probably wasn’t an obvious approach coming into the year, other than to throw him as many cutters as possible.
Breaking things down further on types of fastball: Bellinger has had more years where he handled sinkers reasonably well, but struggled against four-seamers (and has always struggled with cutters, as many lefties do). Four-seamers and cutters always should’ve been the plan against Bellinger, it looks like to me. I think Petriello is onto something, even if what’s happened in September has some noise in it.
About that. Maybe this four-seamer-and-cutter-heavy approach should be obvious to opposing teams, given his long swing, but it seems like, for whatever reason, teams weren’t really getting aggressive with fastballs overall until this month. Maybe it’s because of the match-ups? Maybe they have been more favorable to have pitchers who COULD execute more four-seamers and cutters? Looking at all months of his career, there have been a few monthly spikes in fastball usage up toward 65%, so maybe that’s all this is: small sample match-up-related noise.
I have no firm conclusion here, again, because the samples are still so small, and the results have actually been kind of mixed. Bellinger has struggled lately against fastballs – probably especially cutters – but that has intermittently been an issue for him during his career. The fact that he’s seen more fastballs this month, and his numbers are down, might simply be the product of match-ups, rather than some scary new trend. We’ll just have to see what happens over the season’s final two weeks. Hopefully the Cubs face lots of pitchers who don’t throw four-seamers and cutters!
