The Boston Red Sox have too many outfielders. This isn’t news; it’s been clear for a while now that their outfield is overcrowded, and while shipping Yoenis Cespedes to Detroit for Rick Porcello alleviated the problem to a degree, they still don’t have enough at-bats to go around for the guys they’re going to bring to spring training. It’s a nice problem to have, of course, but it’s still an issue that the team will have to work towards solving.

The Washington Nationals have too many starting pitchers. Well, kind of; you can never really have too many starting pitchers, since the attrition rate of guys who throw a baseball for a living is so high, but Max Scherzer’s signing does push Tanner Roark out of the initial starting five. Having a solid group of useful starters behind your starting five is important, but having Roark as your sixth starter is something of an embarrassment of riches.

The Red Sox could use a frontline starting pitcher, as Rick Porcello isn’t exactly a classic #1 starter on a team that is hoping to make a deep playoff run. The Nationals could use a long-term solution at second base, and if that guy could also provide outfield depth for 2015, that would be even better. There might not be another situation in baseball where two teams theoretically match up for a deal better than the Red Sox and Nationals. So, Misters Cherington and Rizzo, let’s make the case for a Stephen Strasburg/Mookie Betts trade.

Why Boston Should Do It

The Red Sox currently project as baseball’s fourth best team, according to our calculations, and enter 2015 as the slight favorites to win the AL East. Despite their miserable 2014 performance, this is a good roster, and one that is built to contend this season. Boston didn’t spend $190 million on Hanley Ramirez and Pablo Sandoval to move towards the middle of the pack; this team was constructed to get back to the postseason this year.

And yet, this rotation feels incomplete. I like a lot of the pieces they have, and I think both Porcello and Wade Miley were shrewd acquisitions, the kinds of solid rotation pieces that every good team needs. But these are the guys you want starting once in a playoff series, and they’re currently the team’s two best starters, with a couple of lottery tickets and a lower-upside fifth starter behind them. The Red Sox starting five feels like a fantastic middle-to-back-end of the rotation, and if Porcello-Miley-Masterson-Buchholz-Kelly were their #2-#6 starters, we’d be talking about this as a position of strength.

You don’t need an ace to win the World Series, but as Madison Bumgarner just displayed a few months ago, it sure helps. October baseball is different, and the more frequent off days allow teams to allocate a higher proportion of their innings to their best few pitchers. Having a dominant starter make two starts and a relief appearance in a seven game series gives you a distinct advantage, but the Red Sox currently lack the kind of arm that can be deployed in that way.

Stephen Strasburg could be that pitcher. Over the last three years, he’s #3 in baseball in xFIP-, behind only Clayton Kershaw and Felix Hernandez. He’s an ace with upside, and at just 26, he wouldn’t have to be a short-term rental. While he’s only under control for two more seasons, the Red Sox have the financial flexibility to sign him to a long-term deal, and getting him acclimated to Boston ahead of time may give them an advantage in the negotiations. Unlike most pitching acquisitions, Strasburg doesn’t have to be a short-term patch. This is a guy that can provide value both now and in the future.

I know they love Mookie Betts, and so do I, but as much as they value Betts’ overall skillset, the fact remains that he’s a worse fit in Boston than he is on just about any other team in baseball. Betts was considered a plus defensive second baseman in the minors, but the Red Sox have second base blocked off, forcing him to the outfield. But even center field isn’t clearly available, with Rusney Castillo and Jackie Bradley Jr still around, and so if the Red Sox keep Betts for the long-term, he may end up playing primarily right field.

Defense is important everywhere, and as Shane Victorino has shown, this skillset can still result in an impact right fielder, but there are fewer opportunities to utilize a defensive asset in right field than there are at second base or in center field. Betts doesn’t lose all of his value in right field, but he would lose some of it, especially because Victorino is still around for another year.

Right now, we have Betts projected for 385 plate appearances between second base, center field, and right field, and being a legitimate contributor to the roster as a super utility guy: his +2.4 WAR projection for 2015 would make him the game’s best 10th man. But if you reallocate those 385 plate appearances to the rest of the guys on the roster, you don’t actually lose all that much short-term value.

If you split Betts’ 210 center field plate appearances evenly between Castillo and Bradley, their projected total WAR from the position would go from +3.8 to +3.3, a half win drop. They’d lose another quarter of of a win by shifting the non-Pedroia second base at-bats to Brock Holt and a quarter of a win by sliding Daniel Nava and Allen Craig into the right field at-bats that don’t go to Victorino. So, all told, losing Betts costs them roughly one win over his actual internal replacements in 2015.

Meanwhile, Strasburg is probably a three win upgrade over Joe Kelly, especially because Kelly allows the team to use Brandon Workman as a reliever, where he has shown legitimate potential. Because every team needs more than five starters, Kelly doesn’t actually lose that much value, and many of Strasburg’s additional innings would come from guys who should probably spend a good chunk of the year in the minors.

In 2015, swapping Betts for Strasburg is probably something close to a two win upgrade for the Red Sox. It doesn’t sound like a huge difference, but the Red Sox are at the point where wins are highly valuable, and Strasburg is the kind of asset that could be leveraged to an even larger degree in October. While the upgrade is probably smaller in 2016 — with Victorino set to be a free agent, Betts would be able to play most everyday — the Sox still have Allen Craig under contract and Bradley in the organization, so they wouldn’t be dropping down to zero value replacements.

And while they would be surrendering four years of Betts’ prime during years in which Strasburg could theoretically be pitching for someone else, some of that is offset by the ability to exclusively negotiate a long-term extension or get a draft pick as compensation if he leaves. There’s no question that you’d rather have four more years of Betts’ production than either of those options, but the lost value is deferred several years into the future, and the Red Sox should be willing to trade future wins for upgrades in the next two years. Strasburg would represent the kind of upgrade that would make giving up Betts’ future worthwhile.

Why Washington Should Do It

This is maybe the harder sell, because I just argued for the present value of wins taking precedence over longer-term upgrades for contenders. And clearly, the Nationals are also in win-now mode, especially after adding Scherzer to the mix. And with Doug Fister and Jordan Zimmermann set to become free agents at years end, trading Strasburg could mean that the team could enter 2016 with only Scherzer, Gio Gonzalez, and Tanner Roark as stable rotation options. In a year, the Nationals could easily have a significant hole in their rotation if they traded Strasburg away.

But unlike with Boston, Betts fits their organizational weaknesses perfectly, and Strasburg represents more of a luxury than a need. With Jayson Werth likely to begin the season on the disabled list, there’s an everyday job waiting for Betts in Washington, and for the first few months of the season, he’d essentially be replacing some combination of Nate McLouth, Mike Carp and Tyler Moore, both of whom have some value as first baseman but little as outfielders. Even when Werth returns, Betts would have few problems playing everyday for the Nationals, as the Nationals outfield depth was diminished with the Steven Souza trade, and Yunel Escobar is not so valuable that he couldn’t be easily moved to a part-time role to free up time at Betts’ primary position.

In Washington, Betts probably projects as a two or three win upgrade over their internal positional options, especially if Werth’s shoulder proves to be a lingering issue. So while Strasburg is indeed an excellent starter, it’s not completely clear that the Nationals would actually be dramatically worse off in 2015 by making this trade. Strasburg is probably two to three wins better than Roark, and you’d have to also account for some of Roark’s current innings going to lesser options, but even on the high side, you’re looking at a three win drop-off in the rotation, and if you buy into Roark as a guy who can induce weaker-than-average contact, the gap is probably closer to two wins.

The 2015 Nationals wouldn’t be demonstrably worse with Betts than Strasburg, even though Strasburg projects to be the better player. Their high replacement level at starting pitcher and their very low replacement level behind their penciled-in starters in the OF and at 2B mean that the gap between the two players would be reduced in Washington, not emphasized as it would be in Boston. And Scherzer’s acquisition reduces Strasburg’s value in October as well, as there are only so many October innings to be allocated to starting pitchers. Using Scherzer as the Game #1/#5 starter sets him up to pitch in relief in Game 7, but likely excludes Strasburg from that potential third appearance; the first ace provides a lot more marginal value in the postseason than the second one.

So if the Nationals wouldn’t take a significant step back with Betts in lieu of Strasburg in 2015, the rest of the calculation is actually pretty easy. Next year, Betts moves into a full-time second base role, where he projects as roughly a three win everyday player making the league minimum, and the savings in 2016 salary could be applied directly an extension for Jordan Zimmermann. The assumption has been that Zimermann is not going to be re-signed because the team had to keep it’s future salary available to try to re-sign both Strasburg and Bryce Harper, but with Strasburg out of the picture, a long-term deal for Zimmermann becomes more palatable.

And even if Zimmermann isn’t re-signed, the difference in salary alone gives the team roughly $12 million of budget room that Strasburg would have eaten up, giving the Nationals a chance to offset the difference in expected value between the two by upgrading other parts of the roster. Even if you’re low on Betts, and see him as something more like an average big leaguer going forward, an average player plus $12 million in spending money isn’t a huge step back from a $12.5 million Strasburg.

And then there’s the 2017-2020 value, where the Nationals would have four prime years of an athletic second baseman, one at pre-arb and three at arbitration salaries. With ownership already pushing the costs of the present team into the future, stockpiling valuable assets who will make pennies on the dollar is the best way for the Nationals to build a sustained winner, and Betts is exactly the kind of player that the team will need in order to be able to try and keep Bryce Harper in D.C.

And while Betts’ carries the risks of a young player with just 200 big league plate appearances, the risk surrounding Strasburg may be just as high, especially with Tommy John surgery already on his resume. There’s no question that Betts could struggle to adjust to the big leagues, just as there’s no question that Strasburg’s elbow could go out again on any given pitch. The Nationals would be exchanging health risk for performance risk, but it’s not entirely clear that they’d actually be increasing the expected variance of their roster by making the move.

The TL;DR Summary

Swapping Betts for Strasburg would likely make the Red Sox two to three wins better in 2015, and probably a win or two better in 2016. The marginal value of these upgrades, along with the opportunity to try and sign Strasburg long-term before he hits free agency justify giving up the extra four years of control over Betts’ future, especially for a team in their market.

Swapping Strasburg for Betts might not make the Nationals much worse at all in 2015, while freeing up additional payroll space for 2016 to potentially retain Jordan Zimmermann. Strasburg’s postseason value is diminished by Scherzer’s addition, so he’s more of a luxury than a necessity for the team at this point. The Nationals will not be able to retain all of their young talent without supplementing the roster with productive low-cost players, and Betts is exactly the kind of player they should be targeting in a trade.

In talking with people in the game, neither side seems comfortable with the deal, which suggests that perhaps it’s a reasonably fair proposal, or at least in the ballpark of being reasonable on both sides. I know I’m higher on Betts than most, and if you place a very high value on frontline pitching, perhaps you think the Red Sox should add a sweetener to the deal. This isn’t so much about trying to say that Betts are Strasburg are equivalent in value as it is to say that the Red Sox and Nationals are currently setup to help each other about as well as two organizations have been in some time.

It’s almost certainly not going to happen, but as far as speculative trade suggestions go, this one seems to make as much sense on both sides as any I can remember.