AccuScore: Burnett adds 7 wins for Yankees

The New York Yankees shelled out almost a quarter of a billion dollars to upgrade their rotation with CC Sabathia and A.J. Burnett. New York lost their two best starting pitchers from the 2008 season, with Mike Mussina retiring and Andy Pettitte currently a free agent. The Sabathia signing provided the Yankees with a mild upgrade over the 2008 team that featured Mussina and Pettitte, giving the Yankees a 90-72 record in AccuScore simulations of the 2009 season.

When Sabathia was signed, AccuScore simulated the Yankees with Derek Lowe also in the rotation, and found that New York would finish with a 97-65 record. The addition of Burnett instead of Lowe achieves the same result, with the 2009 Yankees now slight favorites to win the AL East over the Boston Red Sox.

The current Yankees rotation projects to be Sabathia, Burnett, Chien-Ming Wang, Joba Chamberlain, and possibly Alfredo Aceves, who went 1-0 with a 2.40 ERA and a 1.17 WHIP in 30 innings last year for New York. Aceves showed promise, minus a four-run, four-inning start against the Red Sox, which raises a question as to whether the Yankees would be better off giving him the fifth spot in the rotation, rather than shelling out money to bring back Pettitte or bring in Lowe.

The 30 innings that Aceves pitched was a very small sample size, and no conclusions can be made from his numbers during that small stretch. It is unlikely that Aceves would have a 2.40 ERA the entire year, but that’s not to say he will have an ERA similar to the disappointing numbers the Yankees saw from Phil Hughes and Ian Kennedy last year. Current AccuScore simulations assume Aceves will fall somewhere between that 2.40 ERA and the 6.62 ERA that Hughes put up. In other words, he’s performing like a good back of the rotation pitcher, with an ERA between 4.00 and 4.50.

This "good version" of Aceves would provide the same value to the Yankees as Andy Pettitte, and would be three to four victories worse than Derek Lowe. This version is currently rounding out the new rotation that is winning the AL East in AccuScore simulations.

If Aceves ends up being like the 2008 version of Phil Hughes, the Yankees would see their 2009 AccuScore projections drop by four wins, making the Red Sox the favorites in the AL East, with the Yankees and Rays battling for the wild card spot. The "bad version" of Aceves projects to be four victories less than Pettitte, and about seven less than Lowe.

The Yankees have considerably upgraded their rotation with Sabathia and Burnett, but at the moment they are gambling on a breakout season by Aceves, Hughes or Kennedy.