New York Yankees pitcher Joba Chamberlain reacts on the mound...

New York Yankees pitcher Joba Chamberlain reacts on the mound as Seattle Mariners' Jose Lopez runs the bases behind after hitting a grand slam during the eighth inning. (July 10, 2010) Credit: AP

Even the best teams have flaws, and for the Yankees, it's the bullpen.

Yankees starters have accounted for 48 of the team's major-league leading 56 wins, and 22 losses. CC Sabathia, Andy Pettitte and Phil Hughes alone are 34-7, an incredible mark.

But the bullpen is a different story. The Yankees rank 19th in the majors with a 4.14 ERA out of the pen, and that's including Mariano Rivera's 1.05 with 20 saves in 22 opportunities.

As a relieving corps, they've blown 11 saves, which is just three behind the atrocious Arizona pen for the most in the league. So who's to blame?

Look no further than Joba Chamberlain (pictured). Sure, we see the obvious blowups, like the grand slam he allowed to Jose Lopez of the Mariners on Saturday in a 4-1 loss.

But to know just how bad the 24-year old has been, you have to go inside the numbers. In six of his appearances (a total of four innings), he's allowed 19 earned runs. In four of those six games (all Yankee losses), the team led at the time Chamberlain entered, and in another, it was tied.

So Joba has single-handedly cost the Yankees five games, or 15.6 percent of their losses on the year (quite a high figure). In his other 33 appearances (33 1/3 innings), he's only allowed five earned runs for a 1.35 ERA. So if he could just nip the blowups in the bud, the Yankees could have a reliable eighth-inning man.

As far as the rest of the pen, Damaso Marte has to be looked at as the second best reliever on the team. Lefties are batting just .146 off him, but his K/BB ratio is nothing to write home about at 12/11.

Chan Ho Park has allowed 34 hits (including six homers) in 37 2/3 IP, David Robertson has walked 17 in 29 2/3, and Chad Gaudin has given up nine homers, just six fewer than Javier Vasquez, in more than 60 fewer innings.

Obviously the pen is something to bear watching the rest of the year, especially if the Yankees can't add another arm by the July 31 trade deadline.

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