The Teams That Should Be Buying And Selling At This Year’s Baseball Trade Deadline

Major-league teams are on the clock and must decide whether they want to buy or sell — and this decision comes with perhaps more urgency than in any previous July. MLB’s annual trade deadline is one week away, and the deadline carries a new sense of finality this season, as baseball eliminated August waiver trades in favor of a single July 31 cutoff for deals. Although the early read on the market has been one of uncertainty, at the very least we should see an intriguing chess match develop between rival general managers in the leadup to next Wednesday afternoon.

Granted, we don’t exactly know how those GMs will react to the compressed timeline when making deals this year. But here at FiveThirtyEight, we do have a tool to help assist with the overall deadline decision-making process: the Doyle Number. (So named for an infamous 1987 Detroit Tigers deadline trade when they shipped future Hall of Famer John Smoltz to Atlanta for pitcher Doyle Alexander.) Basically, Doyle measures the amount of future talent (i.e., total projected wins above replacement added over the next six seasons) a team should be willing to give up — in the form of prospects or other team-controlled assets — in exchange for adding an extra WAR of rental talent in 2019, with the goal of maximizing its total expected championships in both the short and long term.

In other words, Doyle is all about the tradeoff between how adding talent improves a buyer’s present-day championship odds and reduces those odds in the future.¹ So when we say the Los Angeles Dodgers have a Doyle Number of 2.17, it means they should be willing to sacrifice 2.17 future WAR in exchange for every WAR of talent they add at the 2019 deadline. (This is a textbook definition of a buyer; the Dodgers’ Doyle Number is the highest in baseball.) Meanwhile, the lowly Tigers are clear sellers: They have a Doyle of 0.00, meaning there is literally no amount of rental talent they could add this season that would justify giving up any future WAR.²

Those are the easy cases. A team with a Doyle Number around 1.00 has a tougher choice, and would essentially be equally served by either buying or selling, depending on the particulars of a given trade. Here are the Doyle Numbers for each of 2019’s MLB teams, taking into account games played through July 22:

One of the key lessons from Doyle is that the best candidates to buy at the deadline aren’t the ones that conventional wisdom might suggest. Instead of teams that are on the cusp of the playoffs, the most committed buyers ought to be teams whose playoff odds are already solidified — but whose World Series chances could get a big boost with a few important additions. This is a consequence of how talent relates to winning championships in baseball: Because even the best teams usually only have a 15 to 25 percent chance at the title, a mega-talented roster can still get a sizable increase in World Series odds by adding extra star power. As long as it doesn’t create too many positional logjams (and even those can be worked around), there are effectively no diminishing returns between your team’s talent and its odds of holding a parade in November.

Of course, you also have to possess prospects that will convince sellers to part with veteran talent. Among the teams with the highest Doyle numbers, the best farm systems belong to the Atlanta Braves, Houston Astros, Minnesota Twins, Dodgers and — to a lesser extent — Cleveland Indians, according to FanGraphs’ estimates of total farm-system value. (The Tampa Bay Rays also have an incredible amount of prospect talent in their pipeline, though their Doyle of 0.75 suggests a slight preference towards selling, not buying, despite the team’s position in the thick of the American League Wild Card race.)

Houston and Minnesota are in particular need of pitching, in a year when the most desirable trade targets are disproportionately pitchers. So if the Astros deal for, say, Texas Rangers starter Mike Minor (whose long-term track record is that of about a 5-WAR pitcher³ per 162 games), Doyle says the Astros should be willing to part with as many as 12 wins of future talent to add Minor’s five wins to their current talent level. Each amount — five wins now or 12 over the next six seasons — is worth about 0.071 expected championships added.

Not every team has such a stark split between the importance of present wins and future ones. The Washington Nationals, for instance, are one of the teams whose Doyle is currently closest to 1.00, the point of true indifference between buying and selling. They could buy 5 WAR of current talent and have it be worth the equivalent of 1.3 additional WAR in the future, so it would still make sense in terms of balancing expected championships. But they could also sell 5 WAR of current talent, and get back the equivalent of 2.3 extra future WAR if we again assume the championship odds are balanced. This is a delicate situation, although it also can give a team many options in the trade marketplace. Here are all of the 2019 teams who could either add or subtract players — in increments of either 2 WAR (a solid regular starter, per Baseball-Reference’s WAR guide), 5 WAR (an All-Star level player) or 8 WAR (an MVP-level player) of present-day talent — and still potentially create a surplus in total wins after balancing the championship odds:

When it comes to teams on the buy/sell fence, the details of their trade options are important. The Milwaukee Brewers — who have just 84 wins of talent on their roster, a 40 percent chance of making the playoffs and 2 percent World Series odds — could only get a big surplus from buying if they were to somehow land an MVP-caliber player⁴; otherwise, they’d get a lot more out of just selling assets and reloading for the future. By contrast, the Chicago Cubs would only make sense as sellers if they blew up everything and got a massive haul of prospect value back in return. But the Oakland A’s, St. Louis Cardinals and Boston Red Sox, in addition to the Nationals, could benefit from either buying or selling, as long as they commit to a strategy.⁵ In fact, for all of these teams, some kind of activity at the deadline is better than standing pat and doing nothing.

A few interesting teams are not on that list of on-the-fence clubs. The San Francisco Giants have played themselves into the larger deadline conversation in the media, thanks to a recent stretch of surprisingly good play (they’re 15-3 in July). But Doyle says holding onto rumored trade candidate Madison Bumgarner would be a big mistake. With 77 wins of underlying talent (according to Elo) and a still-slim 8 percent playoff probability, even a massive 10-WAR improvement in current talent (think trading for Mike Trout) would result in a net long-term loss of expected championships if bought at a fair price.⁶ Just let the dynasty end already!

Likewise, the Rangers, Philadelphia Phillies and Arizona Diamondbacks — all teams with .500 records or better — are logical candidates to make a deadline push based on traditional baseball thinking. But similar to San Francisco, Doyle sees the Rangers as a team with 75-win talent who has overachieved to its current record and, trailing three division rivals in the standings, possess less than a 1 percent chance of making the playoffs. With attractive trade assets such as Minor and fellow starter Lance Lynn potentially on the block, Texas would be well served to sell. Philadelphia and Arizona have better talent than the Rangers, but neither has much chance of winning their respective divisions, so the wild-card game appears to be each team’s ceiling. Doyle explicitly accounts for how much that fact slices into a team’s World Series odds, which helps explain why each team has a Doyle Number under 0.50. (Then again, I would have considered the Phillies a good candidate to buy a month ago, so these things can change quickly.)

Whatever happens over the next week, it should be fascinating to watch teams react to the finality of this year’s deadline. Even before the new hard July 31 cutoff, deadline activity has been increasing in the past few seasons anyway, and recent history tells us the deals made now could have a significant effect in the postseason. While there aren’t as many massive rental-candidate stars on the market as last year — maybe Arizona’s Zack Greinke qualifies? — the added sense of urgency could keep things interesting, whether teams follow Doyle’s advice or not.

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