The Mets, White Sox, and Brewers are throwing their starters out on short rest in an attempt to secure a playoff spot. Are they making the right moves?
The easiest case to consider is the Brewers'. By moving C.C. Sabathia up to Sunday, they lose him for Game 1 of the NLDS. However, if they throw him on short rest in Game 2, he can still come back and pitch Game 5 on normal rest, so the cost to their NLDS chances is minimal assuming they go this route. Since Sabathia is a huge upgrade over Dave Bush in Sunday's game to secure a playoff birth, this was the right move. Specifically, it improves their Wild Card chances from 77.2% to 80.2%, and their World Series probability from 7.7% to 7.9%.
Even though Sabathia is slated to start Game 5, it would still greatly benefit the Brewers to win the first series in four or less; then they would likely set up Sabathia up for Games 1-4-7 in the NLCS.
On to the Mets. After moving Johan Santana up to Saturday, they will likely keep him on normal rest and have him pitch Games 2 and 5 of the NLDS. This means they essentially aren't penalized at all once they reach the playoffs. The question is whether Santana and Oliver Perez, both on short rest, are a better combination than Jonathon Niese and Santana on normal rest. They are; this move improves their playoff chances from 20.1% to 21%, and their World Series number from 1.9% to 2.0%.
Finally, the White Sox. They're potentially bringing back their whole rotation on short rest for the next four games to decide the division title. What this really boils down to is how to line up their starters:
A) Vazquez-Buehrle-Floyd-Danks (all short rest)
B) Richard-Vazquez-Buehrle-Floyd (all normal rest)
C) Richard-Vazquez-Buehrle (all normal rest) -Danks (short rest)
Ozzie Guillen probably considered options A and B, and given the choice, I would have taken A. The dropoff from Danks to Richard isn't worth giving everyone normal rest. Furthermore, plan A gives their top two starters more time to recover and pitch in the ALDS.
However, plan C is the best of all. Richard isn't that much worse of a pitcher than Floyd (cue hate mail) and he'd be facing an Indians lineup that's more dangerous from the left side of the plate. Meanwhile, the Sox are gaining three key days of rest for their pitchers, and they can still set up the postseason rotation so Vazquez pitches two games in the ALDS while missing only one day of rest. This setup would improve Chicago's Wild Card chances from 32.5% to 33.9%.
I suspect Ozzie didn't give any thought to this plan, partially because he can't look past the respective ERAs of Floyd and Richard.
Happily enough for the Sox, though, their playoff chances are about to improve by accident, assuming that Ozzie keeps his rotation on normal rest in the playoffs. By starting Vazquez twice instead of Buehrle, their chances of winning a 5-game series against Tampa improve from 38.9% to 40.5%.