With the three best free-agent starters already signed, Madison Bumgarner had risen to the top of the remaining crop, as he and Hyun-Jin Ryu were clearly better than the other starting pitchers still on the market. Bumgarner seemed like an ideal fit for a number of contenders, including the Los Angeles Angels. So it was a mild surprise to see the Arizona Diamondbacks, who had just moved Zack Greinke's massive contract in July and had supposedly shopped Robbie Ray, jump in with a five-year, $85 million deal to make Bumgarner their nominal ace.
Greinke was the only Arizona starter to be worth more than 2.4 WAR in either the Baseball-Reference or FanGraphs version of the metric, and he's gone; so if the Diamondbacks wished to contend again off an 88-win season, a rotation upgrade was probably the most valuable move they could make. They had only three returning starters who pitched a full season in 2019, counting Alex Young and his eight minor league starts (and 6+ ERA in Reno), with their remaining rotation options either coming off injury-plagued campaigns (Luke Weaver, Jon Duplantier) or ineffective ones (Taylor Clarke, Mike Leake).
In a return to health last season, Bumgarner was worth 2.8 and 3.0 WAR in the two systems, which makes him (on paper) the best starter in the Diamondbacks' rotation. His 207⅔ innings would have led the club by a wide margin -- and he probably is replacing someone down around replacement level.
Bumgarner and Ray become the D-backs' 1-2 or 2-1 -- the order doesn't really matter -- ahead of a slew of options for the remaining three rotation spots, with Zac Gallen and Merrill Kelly probably taking two of them. The D-backs now have real rotation depth, with the potential to use someone like Weaver in a long-relief role or to trade some of their pitching staff (Duplantier?) to get a regular right fielder -- their weakest position on offense last season and a spot where they lack an incumbent.
The obvious downside of the deal is its length, as projecting Bumgarner out five years for his ages 30 to 34 seasons probably would involve a fair amount of lost time to injuries and likely some decline in effectiveness because he depends so much on his fastball and slider -- pitches that require good arm speed. But Arizona is paying him more like a mid-rotation starter, so if the D-backs get three seasons similar to his 2019 campaign, they probably will consider it money well spent. And he does boost their odds of a playoff spot right now, especially since some of his suitors were their direct competitors in the Los Angeles Dodgers and San Diego Padres.
I thought the Angels might be in on Bumgarner, as they have a glaring need for a starter at this point, and $17 million a year for him would have been an exceptional deal that would have allowed them to also go pay for a lower-tier, back-end starter. The options for their rotation keep dwindling, with only Ryu and Wade Miley remaining from my top 20 free agents, although Dallas Keuchel (ranked 31st) also would be an ideal fit.
The Dodgers aren't in quite the same boat -- they have internal options and more pieces they could trade for a starter -- but I imagine they're less than thrilled to see Bumgarner go to a direct rival and the team that right now has the best chance to catch them for the National League West title.