Hey Babe Ruth ... meet Cody Bellinger

Dodgers slugger challenging record for highest WAR in a season

May 30th, 2019

After the Dodgers completed a wild comeback to beat the Mets on Wednesday night, they've now played 56 games. That means the first third of the season is over, and they're now two games into the middle third. That's another way of saying "it's early, but it's not that early anymore," because while it's still not quite June yet, the season started all the way back in March.

This is all a preface to making the point that it's getting far enough into the season that it's not too early to ask the question that now needs to be asked: What is it going to take for this Cody Bellinger season to go from "incredibly impressive" to "actually historically great?"

If it feels like we talk about "best ever this," or "most historic that" a lot these days, well, maybe we do, and maybe we should, because we're witnessing what is almost certainly the most talented group of baseball players in baseball history. But in Bellinger's case, it's deserved, because this start -- .382/.469/.770, a .503 wOBA in 228 plate appearances through Tuesday's games -- is truly something else.

Dating back to the dawn of the live-ball era in 1920, there have been nearly 10,500 player seasons where a hitter has collected at least 220 plate appearances through the end of June. (That date selected to account for the fact that seasons began much later decades ago, but that we're not trying to find partial playing time full seasons, either.)

Of all of those seasons, only 26 have gotten off to a better batting start than Bellinger's, based on wOBA. You can view the full list here, but understand that we're talking about the best of the best -- six seasons from Babe Ruth, three apiece from Barry Bonds, Lou Gehrig and Mark McGwire, two apiece from Rogers Hornsby, Stan Musial, and Mickey Mantle. (Plus: Jose Bautista's 2011 breakout.) If you have a better start than Bellinger's had, you're going to have an all-time season.

That's enough to give us confidence this is worth looking into, but remember, it's not just about hitting. Since Bellinger proven himself to be elite not just at the plate but also on the bases and in the field, he's already piled up 5.4 Wins Above Replacement (Baseball Reference version) through a third of the season, easily the most in the game.

Last year, Mookie Betts won the AL MVP with 10.9 WAR. Christian Yelich won the NL MVP with 7.6 WAR. Those are full-season numbers. It's not that WAR is a perfect and infallible measure of value, because it's not, but it works well enough and there's been a well-proven correlation between "lots of WAR" and "tons of baseball value."

Bellinger, at 5.4 WAR through one-third of the season, would be on pace for 16.2 WAR, per Baseball Reference. The greatest season in Major League history is Ruth's 1923, when he was worth 14.1 WAR. There are a lot of issues with "on pace," which we'll get to, and we're not saying he will top Ruth, because he probably won't. But it's not too early to talk about it. His start has been that good. He's worth the discussion.

Now: This doesn't mean that he's "better than Mike Trout," because every year someone has a fantastic season that starts those conversations -- last year it was Betts, the year before, Aaron Judge -- and then we remember that part of Trout's greatness is his consistency, that he does this every single year, and that this year he's still quietly humming along with a .449 OBP and a .565 slugging, tied for the second-most WAR in baseball behind Bellinger.

It means that this version of Bellinger, right now, is playing at a level that we've basically never seen sustained over a full season. If he kept this up... what would it look like?

Here's a brief list of the things that Bellinger leads the Majors in, just to remind you how great his season is going.

First in batting average (.382, a 44-point lead over Josh Bell's .338 mark)
First in on-base percentage (.469)
First in slugging percentage (.770)
First in RBIs (51)
First in OPS (1.239)
First in OPS+ (223)
First in Weighted On-Base Average (.503)
First in Weighted Runs Created Plus (218)
First in Wins Above Replacement (5.4)
First in Defensive Runs Saved (15)
First in Five-Star Plays on defense (3, tied with Byron Buxton)
First in defensive Wins Above Replacement (1.4, tied with Lorenzo Cain)
First in average home-to-first time (3.89 seconds)
First in Sprint Speed among Dodgers (29.2 ft/sec), and third among MLB RF

He's also got seven outfield assists, second-most in the Majors. The last player to have that many assists along with 19 or more homers in their first 52 games? Ruth, in 1932. This is the company we're talking about here.

No regular player has cut their strikeout rate from 2018 as much as Bellinger has, by 10.3 percentage points. Only three players have cut their ground-ball rates more than his drop of 12.2 points. No one has added more line drives, as his jump from 19.9% to 34.6% is baseball's best. No one has added more OBP, as he's up 126 points from last year, and only Derek Dietrich has added more slugging.

When you see a player flirt with .400, as Bellinger has done for most of the first two months, you expect to see that he's been the benefit of good luck. But that hasn't really been true, not so far. Bellinger has hit .382, and his expected average -- based on the usual outcomes of exit velocity and launch angle -- is .390. His BABIP is .371, and his expected BABIP is .419. His wOBA is .503, and his expected wOBA is .506.

That's not the same thing as guaranteeing that it will keep up. It's saying that this isn't just good fortune. He's earned everything he's had, perhaps more. If you're looking for evidence of an impending collapse that would prevent him from challenging history, it's not here.

Back to the question at hand, about the historical significance of all this. If Bellinger keeps on doing what he's done in the first third of the season over the final two-thirds, getting up to 16.2 WAR, then yes, it would probably be the greatest season of all time.

That's precisely why it isn't likely to happen. To do what he's done over two months is incredibly difficult. To do what he's done over six months is borderline impossible -- and we're starting to see that somewhat, with his May OPS of 1.027 being somewhat less than his March/April OPS of 1.397, which was merely the second-best month in the entire history of the Dodgers.

Still, what he's done so far is banked. It counts, and it can't be taken back. He's here sitting on 5.4 WAR, with two-thirds of the season left to go; fewer than 20 position players were more valuable than that in the entire 2018 season.

That's what projections are for. You can't assume that he'll just endlessly keep doing this with no change, especially because we've already seen that April was somewhat better than May. The ZiPS projection system, for example, which is accounting for the massive changes we've seen from him already this year, suggests that Bellinger could be reasonably expected to add another 4.2 WAR, which would get him to 9.6.

Keep that in mind, then look at this list of the the best hitting seasons in Dodgers history, dating back to 1901.

9.7 WAR -- Jackie Robinson, 1951
9.6 WAR -- Adrian Beltre, 2004
9.6 WAR -- Jackie Robinson, 1949
9.3 WAR -- Duke Snider, 1953
8.7 WAR -- Mike Piazza, 1997
8.6 WAR -- Duke Snider, 1955
8.5 WAR -- Robinson, 1952

You may have noticed that the list is entirely made up of Hall of Famers, other than Beltre, who is sure to gain entry when he's eligible. There's no meaningful difference in tenths of a point of WAR, so if Bellinger merely hits his projections, he would be in the conversation for the best season in the history of one of baseball's longest-running and successful franchises, up there with a bunch of Cooperstown legends.

But projections are, by their nature, conservative. They account for the good and the bad outcomes, the confidence levels in each, and output a number with the highest likelihood of happening. It's worth noting that before the season began, ZiPS projected Bellinger for 4.5 WAR. He's already at 5.4 WAR.

That's not a flaw in the projection. That's a reasonable reaction to a 2018 season that Bellinger will be the first to tell you was somewhat disappointing, especially after his successful 2017 debut. But we're trying to find a best-case scenario here, so let's have some fun with this, and try to figure out just how much he'd need to outdo that to reach baseball history.

Here's the list of players to ever put up 12 WAR seasons, per Baseball Reference. (The FanGraphs version has Ruth's 1923 at 15.0 WAR.)

14.1 WAR -- Babe Ruth, 1923
12.9 WAR -- Babe Ruth, 1921
12.5 WAR -- Carl Yastrzemski, 1967
12.4 WAR -- Babe Ruth, 1927
12.1 WAR -- Rogers Hornsby, 1924

That's it. There's 15 seasons in the 11.0 to 11.9 WAR range -- that's where you'll find Bonds, Gehrig, Mantle, Mays, Cobb and a few more Ruth seasons -- and a few dozen north of 10 WAR, but if you're going to get into the top five ever, you've got to hit 12 WAR.

In order to get Bellinger there, we're assuming that he'll do worse than "just the same thing he's been doing," that .503 wOBA, but better than the already-strong ZiPS projection, a.399 wOBA. We crunched the numbers to reverse-engineer WAR, and, in order to get him another 6.7 WAR over the last four months of the season to get to 12 WAR, Bellinger would need to maintain his current level of defense and baserunning, and put up a batting line that resembles what J.D. Martinez did in 2017:

.303/.376/.690, a .430 wOBA

That was the year that Martinez gathered some down-ballot NL MVP support despite not even joining the D-backs from the Tigers until July. It was the year that he finished tied with Judge as baseball's second-best hitter behind only Trout.

So if Bellinger really wants to get into that all-time elite inner circle, the area that Mays or Trout or Mantle never made it into, he doesn't have to keep doing exactly what he's done so far. He just has to hit like one of the best hitters of the current generation did in his best year, while also adding elite-level defense.

It's not easy. It's not supposed to be easy. The best-ever season by a Dodger seems much more in reach, and it's probably not likely we're talking about Ruth and Bellinger in the same sentence at the end of the season. But the simple fact that his start has been so good that this exercise didn't turn out to be insane tells you something. There are reasons to have these conversations. Bellinger has earned it.