With David Robertson coming off a brilliant 2011 and the indestructible and consistent force that is Mariano Rivera, the back end of the Yankees bullpen was expected to be very strong. And Rafael Soriano would probably be healthier and better than last year; he's got too long of a track record to be written off after one crappy season. Without the Soriano signing to draw attention to it there was less talk of The Formula, but it seemed an assumed part of the plan.

Given a lead, the Yankees had a lot of power bullpen arms to protect it. With improved starting pitching and a still potent offense, there should be lots of leads to protect. But with losing Mariano Rivera for the rest of the season, a long DL stint for David Robertson, and a setback from Joba Chamberlain, the strategy seemed a lot less bulletproof.

Coming into the 2012 season, Boone Logan, Cory Wade, Clay Rapada, Cody Eppley, and David Phelps had combined for 1.7 fWAR in their respective careers. Outside of the three right-handers at the top of the bullpen, it was a collection of thrown together spare parts and young, inexperienced arms.

Rivera, Robertson and Soriano have thrown 49 of the 178 bullpen innings, leaving 129 (72.5% of the total) for the previously mentioned five, Freddy Garcia, D.J. Mitchell, and Ryota Igarashi. Losing Rivera and Robertson, the vast majority of the bullpen load has been carried by an assortment of mops. And yet:

The Yankees bullpen ranks second in the American League in ERA (2.63), second in FIP (3.28), and third in xFIP (3.71).

The Yankees are 29-2 -- a .935 winning percentage -- when leading after five innings (the American League is 345-61, good for an .850 winning percentage).

The Yankees are 33-3 -- a .917 winning percentage -- when leading after six innings (the American League is 372-52, good for an .877 winning percentage).

No one is being over-worked.

Boone Logan leads the team with 33 appearances (on pace for 81 over a full season), but has thrown only 23.2 innings due to LOOGY status. Cory Wade leads the team with 28.0 innings (on pace for 68.2 over a full season), but that's well within reason.

As you'd expect, a part of the success of the bullpen can be drawn back to the length given by the starting rotation. The 178 innings thrown by the Yankees is more than only that of the Angles (176), allowing Joe Girardi to usually keep his bullpen options fresh, but not over-exposed.

Were the Yankees lucky to get this kind of performance from the guys that they had? Of course. No one in the bullpen has bombed this year. No one is even having a bad year. With the volatility of bullpen pitchers and the limited success of the guys assembled, this kind of thing just doesn't happen very often.