Joba Rules 2009 - How The Yankees Can Keep Joba Below 150 Innings And Win

In reading our copy of Baseball Prospectus 2009, we came across an interesting discussion in the Chicago White Sox' chapter about the potential to bring back the four-man starting rotation in Major League Baseball. Stat-heads have long pined for the return of the four-man rotation, since fifth starters are so often painfully below replacement level. Ozzie Guillen wasted too many starts on the fifth starter in 2008, and Baseball Prospectus broke down exactly how the White Sox could have done better with their pitching staff management.

The Yankees don't have the problem of a below replacement level pitcher anywhere in their rotation. What they do have is a young stud pitcher named Joba Chamberlain who can't throw many more than 150 innings in 2009 due to unfortunate injuries in 2008. That leaves the Yankees in a predicament that often devolves into a "Joba should go back to the bullpen" debate. That asinine sentiment aside, the Yankees can easily limit Joba to 150 innings by simply treating his spot in the rotation as if they have a scrubby fifth starter who they don't want to see the light of day.

By Baseball Prospectus' calculations, the White Sox fifth starter would have had to make only 24 starts in 2008 if they had skipped the fifth starter whenever off days permitted. We have not done the calculations for the 2009 Yankees schedule, but we can assume it will be around the same number. If we round up to 25 starts, and we are conservative by giving Joba the league average of 5.44 innings per start, that would leave him with 136 regular season innings. Considering that the Yankees are 6/5 odds to make the World Series, there is a strong likelihood that the Yankee will be playing October baseball, and Joba will be able to continue pitching throughout.

Joe Girardi has indicated that he wants Joba to make 30 starts, even mentioning that he has projected out all 162 games without skipping Joba's turn even once. Again using the conservative estimate of 5.44 innings per start, that would put Joba at 163 innings before the playoffs. After throwing only 100 IP in 2008, throwing 163, plus the playoffs would put Joba in serious danger of suffering an injury due to what is now known as the "Verducci Effect" in 2010. Beyond The Box Score recently had some interesting analysis of the "Verducci Effect."

Girardi has conceded that he will likely have to pull Joba after 5 innings in many starts if he plans on running him out to the mound 30 or more times. With a pitching staff featuring workhorses like CC Sabathia, Chien Ming Wang and Andy Pettitte, why not skip the fifth spot when possible instead of wearing out the bullpen every fifth day? Some will argue that young pitchers only suffer injuries because they are handled too carefully, but when you have a commodity as valuable as Joba Chamberlain, you can never be too careful. Read the full post, after the jump