Rob Neyer seems confident that the Yankees will opt for the division series schedule that gives them a three-man starting rotation--keeping Joba Chamberlain out of the mix--and he's probably right. But is it the right move for New York?
The three-man rotation effectively takes a start from Joba and gives it to Andy Pettitte. I don't believe Pettitte is a significantly better pitcher than Joba, but Chamberlain's August and September stats would scare any manager away. For the sake of argument, let's say Pettitte is the stronger pitcher right now. Why shouldn't the Yankees then choose the three-man rotation? Because we're not considering the other consequences:
a) The Tigers also get to use only three starting pitchers
b) The different rotation setup could affect availability for the ALCS
c) Each team can now use its fourth starter out of the bullpen
The last point clearly favors New York--who cares if Nate Robertson or Eddie Bonine is available for mopup work?--but a) and b) are hurting the Yankees plenty. By opting for the three-man rotation, the Yankees are converting a Robertson/Bonine start into an Edwin Jackson start. Jackson isn't as good as his current 3.36 ERA, but he is far better than the alternatives. Detroit gains much more from a second Jackson start than the Yankees do from a second Pettitte start.
The three-man rotation could also derail the pitching setup for the ALCS. Unless the Yankees sweep the division series, C.C. Sabathia will need to start twice, killing any chance of him pitching three ALCS games. With a four-man rotation, the Yankees simply need to dispatch Detroit in four games or less, which they will do 53% of the time by my estimates.
Even with regards to c)...after Joba's performance in August and September, can you see the Yankees using him in the late innings of a tight October game? Very unlikely. Furthermore, New York's two most prominent bullpen roles are already locked down. At most, Chamberlain will be a seventh-inning pitcher, and those just aren't that valuable.
If the Yankees choose this schedule solely to boot Joba from the ALDS rotation, they're not seeing the full picture.