The Twins, heading into the off season, promised to spend big money on impact pitchers. They did not do this. They missed out on their man (Zack Wheeler) largely due to forces outside of their control. Instead of panicking and signing someone who would have received an impact contract for less than an impact performance (Bumgarner or Keuchel), they signed a couple undervalued assets (Homer Bailey and Rich Hill) who at worst will effectively replace Kyle Gibson and Martin Perez, and at best will be impact players. Rich Hill is very good when healthy.
However, with the pitching market dried up, the Twins made the biggest free agency splash in franchise history, signing former MVP third baseman Josh Donaldson. Instead of shoring up the starting rotation, which will be fairly average, they doubled down on a strength and added a 37-HR hitter to the already lethal Bomba Squad. No, he can’t pitch, but that’s okay.
What makes a pitcher valuable? The ability to prevent runs. What makes a batter valuable? The ability to create runs. So, theoretically, if the addition of Josh Donaldson creates as many runs for the Twins as the difference in how many runs Homer Bailey, and say, Zack Wheeler, give up, then adding Donaldson is just as good as adding Wheeler.
Last season, Josh Donaldson mashed 37 home runs, scored 96 runs, and drove in 94. Hitting in an even more stacked lineup, if Donaldson stays healthy, we should expect very similar numbers this year. He also is excellent at making pitchers work to get him out, which is something that could have quite a domino effect on opposing pitchers. Donaldson walked 100 times last year, which is 40 more than the nearest Twin had. With Donaldson working the count, pitchers will be more prone to tire and make mistakes against the other Twins batters. On the flip side, pitchers may want to avoid this effect by pitching Donaldson less carefully, which will end poorly for them. All in all, Donaldson should be involved in the creation of 150-160 runs, and using Baseball Reference’s Runs Better Than Average stat (pretty self-explanatory), Donaldson ought to be worth about 40-50 more runs than an average player. For reference, C.J. Cron, who Donaldson is effectively replacing, scored -5 Runs Better than Average last year. So Donaldson could add about 45-55 runs to the team.
Furthermore, Donaldson will be far and away the best infield defender on the squad. With Sano sliding over to first, where he will probably be able to be a league-average defender, and Donaldson helping cover for Polanco’s limited range (and already being far superior to Sano over there), the infield defense should be far better than was expected prior to the signing. This will prevent runs.
On the flip side, how many more runs will be given up because we signed Homer Bailey instead of Zack Wheeler? We can’t project improvement, so using last year’s stats, I calculated how many earned runs each gave up, scaled to 150 innings pitched (to even it out). The “has-been” Bailey, who pitched 163.1 innings, gave up 76.3 runs when you scale it back to 150 innings. Wheeler, who pitched 195.1 innings, gave up 66.1 runs/150 (there may be a case to be made about innings pitched here, but Jose Berrios was the only Twins starter to surpass Bailey in innings pitched last year). In conclusion, Wheeler prevented only about 10 more runs than Bailey did last year.
By signing Donaldson and Bailey instead of Zack Wheeler, the Twins have created a (projected) net gain of at least 35 runs. If they had signed Wheeler instead, they would have prevented less runs, but it would have been a net loss versus the alternative. When you throw in the fact that Rich Hill has been indisputably a top-10 starter in the bigs when healthy (and he should be healthy for October), this off-season looks like a three-run bomba from the front office whiz kids.