For months, it seemed all but certain that Ronald Acuña Jr. would win the National League Most Valuable Player Award in a rout – possibly unanimously. Maybe he still will, because he’s certainly done nothing to injure his case; he’s merely hitting .343/.427/.565 this month as the Braves coast to a sixth consecutive division title. But, through no fault of his own, it’s not quite so clear anymore, is it?

That’s because Mookie Betts is finishing off the best month of what’s increasingly looking like a Hall of Fame career. Entering Monday, he led Acuña in home runs, OPS, and both major versions of Wins Above Replacement. While award ballots aren’t – and shouldn’t be – a simple “rank the WAR” exercise, especially when it comes to tiny fractions of a win, both major WAR versions are in exact agreement about the Betts lead has, even after Acuña's 4-for-5 with a homer and two steals performance in Colorado on Monday.

• FanGraphs: Betts 7.2 WAR, Acuña 6.6
• Baseball-Reference: Betts 7.2 WAR, Acuña 6.6

Leading the league in WAR, home runs and OPS, all for a first-place team? Maybe the question is less what Betts’ case is for winning the award, and more what his case for not winning it is.

That’s too glib, of course. What Betts is lacking is the season-long narrative of being the front-runner for the award, which matters a lot. What he’s lacking are the 51 (!) additional stolen bases that Acuña has, likely on the way to history’s first 30/70 season, having already achieved history's first 30/60 season, at that. But if we’re discussing narratives here, then the narrative of Betts answering the call to move from right field to start 53 games (and counting) as a middle infielder, just because his team needed him to, is a strong one in and of itself.

That this is even a conversation (and it is!) says considerably more about the greatness of Betts than it does about any imagined flaw of Acuña's. How did Betts even get here – and how do you define value, anyway?

(A brief moment to acknowledge Freddie Freeman, who is in the midst of the best full season of his own Hall of Fame career; he is, believe it or not, just 10 points behind Luis Arraez for the Major League lead in batting average and may set the Major League record for doubles, each feats which would likely catch the eyes of some voters. He actually leads Acuña in FanGraphs WAR. But since Freeman plays first base and lags Betts in slugging and both Betts and Acuña in home runs, he’s lacking some of that narrative quality that matters when humans vote on awards.

To a lesser extent than that, this applies also to Matt Olson, who will probably hit 50 homers and lead the sport in RBIs, though he’ll lag in WAR due to lack of baserunning value and first base defense that is, by his own admission, not up to his usual standard. With the understanding that a red-hot finish could change the equation, we’ll consider this a two-man race for now.)

1) It took Betts’ best month at the plate to even get here

As of Tuesday, Betts, who spent part of last offseason training with weighted bats at Driveline Baseball, is second in the Majors (behind only Shohei Ohtani) in slugging percentage and OPS, and he’s already tied his own career high with 35 homers.

This is the key, because for most of the season, Betts trailed Acuña in hitting production, and as we noted earlier, Acuña has hardly run into any kind of slump. Instead, Betts has turned it on, in a way that might be easier understood if you look at their respective monthly OPS. It’s indisputable that Acuña got off to a faster start than Betts did, just as it’s indisputable that Betts has had a far better August than Acuña has had. In between? From May through July, Betts had a 1.000 OPS. Acuña had a .989 OPS, which is to say: essentially identical.

The difference is in that first month, and the most recent month. Since Betts’ advantage in August was larger than Acuña’s was in April, the season-long totals reflect that Betts has been somewhat better at the plate, mostly when it comes to power, because he has 11 additional extra-base hits.

Betts: .312/.406/.606, 1.011 OPS, 169 OPS+, 35 HR
Acuña: .335/.418/.572, .989 OPS, 164 OPS+, 29 HR

Betts now holds a 22-point gap in OPS. Acuña has scored nine more runs, and Betts has an edge of 14 in RBIs. They each have excellent strikeout rates and walk rates, both better than average.

But it took until Aug. 20 for Betts to take the lead in OPS, and that’s key here. Given Acuña’s large lead in stolen bases, which we’ll get to in a moment, Betts was pretty much going to have to hit as well or better to make a strong case, which he now finally has – thanks to the best month he’s ever had. It’s one of the best months anyone’s had in the last 10 seasons, actually.

Betts, best months ever, by OPS
1.282 // August 2023
1.200 // May 2018
1.173 // April 2018
1.156 // September 2018
1.103 // August 2020

This gets into “create whatever narrative you prefer” territory, really. If you want to credit Acuña for consistency, feel free to do so. If you want to credit Betts for improving as the season goes on and playing at the highest level as the playoffs near, credit him for that, too. There’s never going to be a right answer there.

Aside from batting average, Betts leads Acuña in most every notable batting metric, including the batting component of WAR (FanGraphs has Betts at 51 batting runs, best in the NL, with Acuña third behind Freeman, at 49). Though Betts isn’t likely to repeat his August, that 22-point lead in OPS seems a difficult one to overcome in the final few weeks, and the projections suggest that they should perform about identically in that regard for the rest of the season, which would be a fitting finale for two elite hitters.

If that happens, Betts will lead in OPS, and he’ll likely lead in WAR, and … well, what would that mean?

2) How rare would it be to lead the league in WAR and OPS and not win the MVP?

“Sixteen of the last 28 MVPs led their league in bWAR,” Benjamin Alter wrote for SABR earlier this year, noting also that only once in the last 15 seasons did an MVP win without finishing with a top-5 WAR total, an indication of the strengthening acceptance of the metric over the years. Having the most WAR in a season doesn’t (and shouldn’t) guarantee an MVP Award, but leading the league in it surely says a lot about how valuable you were. How often, then, does a player lead in OPS, and in WAR? And if they do that, as Betts currently does, how often does that turn into an award?

Since the Baseball Writers' Association of America began voting for MVPs in 1931, a player has led his league in OPS and WAR 80 times. (That’s 43 in the NL, and 37 in the AL.) Only 42 of those seasons ended with an MVP season, or just over half. That seems like a disappointing correlation, except that it’s accounting for all of those seasons from nearly a century ago long before anyone had heard of any such thing.

Maybe it’s more useful to stick to modern times. Just look at how it’s gone since the year 2000:

National League since 2000

• 10 seasons with a player leading in OPS and WAR
• 8 of those seasons saw the player win MVP

The two that didn’t? In 2000, when voters surely did not know how to handle the numbers Todd Helton put up in a pre-humidor Coors Field (he finished fifth), and 2017, which isn’t hard to explain at all, because Giancarlo Stanton was essentially tied with Joey Votto in WAR (7.9 to Votto’s 8.1), but he hit 59 homers on the way to the MVP.

American League since 2000

• 6 seasons with a player leading in OPS and WAR
• 4 of those seasons saw the player win MVP

Again, only two didn’t. That was in 2015, when Mike Trout’s August slump and a non-playoff Angels team helped Josh Donaldson take the prize, and in 2001, when Ichiro Suzuki’s magical rookie season captured the award over Jason Giambi’s WAR lead – again, years before anyone used WAR.

So, you might say that in the last 20 years, the player who leads in OPS and WAR has won 10 of 12 times (83%), a number that is most likely going to change given that Ohtani is sure to lead the AL in those categories as well – and Betts is on track to do so in the NL. To do that, and not win the award, would require a pretty compelling narrative. Fortunately for Acuña, he has one – but so does Betts.

Acuña has 61 steals after two on Monday night, the most in baseball. Betts has 10. If we put that into our super fancy science calculator, we’ll find that Acuña has stolen over six times the bases that Betts has. It’s a lot. It’s so many, and the reasons are various, as MLB.com’s David Adler dove into recently. It’s not just about speed; it’s also, it seems, about being wise enough to realize that the game has changed and aggression is good. This is clearly the largest selling point of any “Acuña for MVP” case, that he’ll end up with nearly unparalleled power/speed numbers, likely ending with a historic 30/70 season. (A 40/70 season, which once seemed possible, now seems unlikely, since he’s hit only nine homers since the start of July.)

But for Betts supporters, there are a few easy counterpoints here. The first is that Acuña has also been caught stealing more than anyone, and making an out on the bases hurts more than gaining a base helps, though that hardly closes the gap. The second is that this year's rule changes have made stolen bases easier to come by than they've been in decades, making comparison to previous stolen base totals difficult.

The third is the in-season move Betts made to (mostly) second base and (occasionally) shortstop, changes necessitated by early-season injuries to Chris Taylor and Miguel Rojas and the July demotion of struggling rookie second baseman Miguel Vargas to the Minor Leagues. Every game Betts has played in the infield is one that James Outman, David Peralta, or Jason Heyward (cumulative .766 OPS) have been able to play, as opposed to more of Vargas.

Entering Monday, Betts has appeared in 92 games in right field, 48 at second, and 16 at short. Here is the full and complete list in AL/NL history of players to appear in at least 15 games at second, short, and any outfield position, in a season where they also hit at least 25 home runs:

• Mookie Betts, 2023

Acuña posting a 30/70, or whatever he ends up at, is an incredibly impressive feat. Betts moving into the middle infield (and back to right, and back again, while hitting equally well at all three of them) is impressive in its own way. Will voters be able to consider either one more impressive? It's an impossible choice.

4) Defense metrics either favor Betts, or neither.

If we really want to invite controversy, let’s put this one out there: Advanced metrics don't necessarily agree on Betts, but they think that Acuña's overall defensive game has been merely around average this year.

• Statcast’s Fielding Run Value has Acuña at -2 runs, and Betts at an even 0.
• Defensive Runs Saved has Acuña at 0 runs saved, and Betts at +7, mostly at second base.

It’s not hard to explain what Statcast sees in the six-time Gold Glover, Betts, and it’s not new. His once-elite speed has declined as he’s aged, and now, at 30, he’s in possession of exactly league-average speed, which can be seen in the fact that he’s now rated as more good-than-great in baserunning. His defense has followed suit as the glove that was once all-world (through 2018) became solid (through 2022) and this year is more average.

For Acuña, on this point, Statcast and Defensive Runs Saved each agree; his tremendously strong and valuable arm, one of the best in the game, helps to counteract somewhat below-average range, making his overall defensive value something like “average.” Statcast has him as -6 on range, and +4 on arm, in part because below-average reads and jumps have turned easier opportunities into harder ones.

What he may lose in defensive metrics, however, he might just gain back in highlight reel plays:

There's actually a highly entertaining world in which Betts wins the utility player Gold Glove award, first handed out last season. But either way, the Betts case here isn't so much "beloved by defensive metrics" as it is "this is not an area where Acuña has a clear advantage in an MVP case."

5) So who really has the edge right now?

Both stars have a track record of success and play for a first-place club, so there’s not much of a differentiator there. Both have a slugging first baseman as their running mate, so there’s a somewhat similar “vote-splitting” factor. If you care about context-dependent stats like win probability, they’re basically tied there, though Betts has a healthy lead with runners in scoring position.

The right answer here is there is no right answer, not right now, as August turns into September. You can make a strong case for either one – or really Freeman, too – and you wouldn’t be wrong, because they’re all deserving. Much like Ohtani vs. Aaron Judge last year, when you have two elite players having truly outstanding seasons, sometimes the only mistake you can make is not appreciating both at the expense of needing to choose a winner.

As things stand, Acuña has the advantage of having held the lead all season long and having done absolutely nothing at all to squander that lead, which is powerful. But at the same time, it's clear Betts has an extremely good case, because that's how well he's played. In September, it’s going to be an extremely interesting race. But it is, at least, that. For the first time, it's now an actual race.