Cody's Confusing Case
Cody Bellinger had his best season in three years, and is now a free agent. How much can one trust his success to continue?
Introduction
Typically, an analyst gets more and more confident about a player's skill set and skill level as they play more games, and a player gets better at filling their given role in turn. This rule doesn't apply to Cody Bellinger, whose constant change in approach and level of performance leads analysts to look like Cody himself in confusion. One could spin a wheel before the season starts to determine whether he'll be a serious middle-of-the-order threat, an average hitter, or a center fielder hitting 8th only because of his defense, because that'd be as accurate as any projection system on the matter. Unfortunately, as a pending free agent once again and at the attractive age of 27, teams must once again decide if signing the former NL MVP to a long-term contract is worth it. This article will be my modest contribution in concert with that evaluation effort.
The Pendulum
The erratic nature of Bellinger's career makes his past essential background to see what characteristics allow him to look his best. This back-and-forth of Bellinger's performance year-to-year is what I call the pendulum.
He took the league by storm in 2017, showcasing solid plate discipline and power while manning a solid first base. The only real weakness in his game was his swing and miss, which led to the 9th worst contact rate in the league amongst qualified hitters and the 3rd worst in-zone contact rate. He dealt with all pitches fine, but his curveball (47.1%) and slider (44.4%) whiff rates were definite concerning causes. In general, though, he hit pitchers very hard with an above-average chase rate, leading to nearly a 12% walk rate. Bellinger's approach was clearly developed beyond his years at that point, at just 21.
In 2018, things swung in the negative direction, primarily from an influx of ground balls that considerably reduced his extra-base hit potential. However, he was still a well above-average player. He made much more contact on pitches out of the zone than his rookie year and maintained similar exit velocities (EV), but that extra contact cost him the ability to elevate the ball. This was especially true for breaking balls, which dropped in whiff rate by 14% overall, according to BaseballSavant, from 2017 to 2018, but at the cost of 3 mph of EV and 15° of launch angle.
2019 saw the peak of Bellinger, where he annihilated every pitch, especially the hard stuff like fastballs and sinkers, en route to an MVP. He hit fastballs hard over 50% of the time and improved his contact rate by 6% to be above average amongst qualified hitters. He swung virtually the same amount during this time as well, meaning he was almost impossible to pitch to. If it were in the zone, he'd usually connect with force; otherwise, he'd let it go. He also had a career-high pull rate of 47%, which had trended upward the prior two years from 39% in his rookie year.
In 2020, he regressed again, but his level of play was much more similar to 2019 than the results may have appeared. He lost a lot of line drives for ground balls and struggled to connect with fastballs at the same level as 2019, but he held the same swing decision patterns as the prior year. His quality of contact remained in the top 15% of the league, and with more time to adjust mid-year, he may have been able to put up a much better season.
2021 and 2022 were, frankly, horrific. Someone must have taken a bat to the pendulum, because it sure didn't swing back to the positive side again. In 2021, Bellinger was below-average against all pitch types, but at the very least, he had no severe weakness that broke his entire approach. In 2022, after improvements against fastballs that got him back to average levels of quality of contact (likely from cheating on them), his performance against breaking balls and changeups plummeted, hitting a comical .205 and .196 xWOBA respectively, on a combined 42% usage. That's worse than Kolten Wong during his Mariners tenure this past season, who was quickly released halfway through the year after failing spectacularly as a platoon hitter. Given his level of ineptitude, I'm surprised Bellinger didn't see any more of them.
He also tried other adjustments; he was more aggressive in the zone than ever in 2021 and was more focused on contact in 2022, but it all led to the same result.
Some have argued that his success relies heavily on his production against fastballs, which varies wildly. Most people would say 2017 and 2019 were his two best offensive seasons, and those two seasons were the only ones where he had a positive run value (RV) against fastballs. 2023 is the third-best in both respects, at -1 RV. It's worth emphasizing, however, that he has always been at his worst when he struggled against breaking balls in 2021, 2022, and, to an extent, 2018.
One could say, then, that Bellinger's key to success is hitting breaking balls. When he doesn't punish breaking balls, he gets completely exploited, and when he struggles against fastballs, he can still put up a solid season if other things go alright (2018, 2020, 2023). While it's uncommon for hitters who are below-average against heaters to be productive, there are some notable names from 2023 in that camp, such as Paul Goldschmidt, Adolis Garcia, and Austin Riley. Bellinger's .323 xWOBA against them isn't even that unproductive, honestly.
The Present Bellinger
Bellinger played his best since 2019 in 2023, and it came with the lowest exit velocity (88 mph), strikeout rate (15.6%), and barrel rate (6.1%) of his career. He did so by maximizing his line drive rate with a high sweet spot rate (83rd percentile) and focusing on contact to a level he never had before. Strangely, his VBA, or swing path angle, is the same as ever, indicating it's primarily a mentality shift rather than a mechanical one. This is supported by his contact rate, which shows that he makes 6% more contact both in and out of the zone than before, despite swinging and chasing at career norm levels. This is a continuation and proper implementation of his 2022 game plan, which had this 'bat on the ball' game plan.
A critical thing that has not been frequently pointed out is that the shift is gone, and with it, a healthy amount of his struggles. Between 2020 and 2022, he had a wOBA of .333 against defenses without a shift, and .284 versus defenses with one. He was shifted against more than 90% of the time in each of these seasons, and his season-high wOBA overall was only .337 in 2020. The average in both cases is heavily weighted by his solid 2020 season, but even in his worst times, he was always better against straight-up defenses. I omitted 2019 because it would skew the data even more, but he did far better against shifted defenses. This is probably because his groundball rate was so low, so the infielders' positioning didn't matter nearly as much.
In 2023, he posted a .386 wOBA against standard setups and a very good .362 wOBA against the more subtle shifts. Bellinger has significantly benefited from the new rule changes, allowing more pulled ground balls to find their way to outfield grass.
Now, Is it sustainable? Well, first, to clear up some misconceptions I've seen:
His BABIP is unsustainably high: He had 75th percentile sprint speed last year with an 83rd percentile sweet-spot rate and 36% groundball rate, according to BaseballSavant, indicating that he is getting plenty of balls at launch angles one wants. Amongst qualified hitters, he finished with the 37th-highest BABIP out of 133. It may be a little high, but it is not a glaring issue.
He's using all fields rather than just pulling: His opposite-field hit rate is identical to the past three years, and his pull rate is the 3rd-highest of his career. The mentality shift is based on making more contact rather than where it's going. This is why the reduction in the shift has been so effective.
He has problems with fastballs: This isn't necessarily untrue, but as mentioned before, a .324 xWOBA and 21% whiff rate in a one-season sample doesn't indicate anything is crazy amiss. It's far better than in the past three years, as well as his solid 2018. He was thrown fewer fastballs in 2023 than in 2019 when he feasted on them. I would have expected a more severe adjustment if that was a pronounced flaw with his game. Given his career trajectory to this point, it's a good sign.
The Future Bellinger
With the BABIP and pull rate likely being sustainable from his career trajectory, I will focus on another element of Bellinger's 2023 that seems unsustainable: his 26 HR in 130 games, or 30 HR/650 PA. A basic linear model using barrel rate, average exit velocity, launch angle, and sweet spot percentage says that Bellinger was expected to have around a 3.1% HR rate, far lower than the 4.7% he posted. Given that 14.1% of his fly balls were home runs with such low EVs and high line drive rates (he was 59th of 258 qualified hitters in flyball EV), I think it's fair to be pessimistic, despite pulled fly balls making up a decent 3.6% of his plate appearances. One should expect 20-25 home runs for Bellinger next year in a neutral offensive park.
Here are some possible scenarios. For ultimate simplicity, I only tinkered with two values: the HR/FB% and the BABIP. Other than hits (which decrease in tandem with BABIP and HR total), all other variables will be held constant. Realistically, a decline in these values would hurt him in extra-base hits, BB%, etc., but this can be seen as an 'upper bound'.
Bellinger’s 2023 if he had different amounts of luck in BABIP and home run rate.
The results show something interesting. A decline in BABIP by nearly 30 pts, a significant drop, would lose him .017 wOBA points, but a drop in HR/FB% by just 2.5% to 12%, a minor drop which is still considered an above-average mark by FanGraphs, drops him nearly the same amount. Steamer projects 25 HR for him next year, so 12% seems like a safe middle ground. If he saw both stats decline severely, he'd only have a .803 OPS despite retaining a great K:BB ratio.
The importance of Bellinger hitting home runs can't be overstated: he provides only average value from walking and very few doubles, considering how many balls he puts into play. With a slight decrease in home runs, his production falls off rapidly. While most people claim Bellinger's high BABIP is a cause for concern, its drop in isolation is not much of a problem because most of his hits are singles, anyway.
One must then ask the following: Is giving him a massive contract for what will be, at best, a .850 OPS and slightly above-average CF defense (5-10 OAA at peak) worth it? Especially if regression to a league-average player is almost guaranteed in a few years, and the player's approach is highly volatile?
Conclusion
I find Bellinger's case a lot more concerning than I used to, and the market appears to agree with me. While he's a great defensive center fielder, nothing screams that he'll be a consistent offensive threat. His case resembles Dansby Swanson's: a young player with a standout year before free agency demanding a hefty financial offer of 7-8 years at $20-25 million. I view Bellinger as a better hitter and a worse fielder at a similarly premier position and, therefore, will probably be compensated similarly. Is he worth that price?
Given that 2023 is his 99th percentile ceiling without a radical adjustment, no. An exception could be made for a team that desperately wants an above-average hitting and defending center fielder with money to spare. Still, there is little chance Bellinger is considered a good signing at the end of the contract he gets without significant improvements to his game or immediate team results. Paying a marquee free agent while praying it breaks even is generally not a good strategy.
Sources:
BaseballSavant
FanGraphs
BaseballReference