When will we know how good the 2011 Yankees can be?

Entering Sunday’s game against the Cubs, the 2011 Yankees are a stronger 2nd place team than they seem. If not for the first place Red Sox, more might be made of the Bombers’ 40-29 record, which is a .580 winning percentage and projects to a 94 win season. But that alone doesn’t tell the entire story. According to Fangraphs, entering Sunday’s game the Yankees led all of the majors in offensive WAR, with 17 and in wOBA at .352. The pitching has been strong as well, with 9.3 WAR (6th in the majors) and a 3.76 team FIP, good for 10th in the majors.

The Yankees, therefore, have gotten off to a strong start using the same formula they have for the past couple of seasons. In 2009 and 2010 the Yankee put the game’s best offense on the field, and relied on at least good if not great pitching to put together deep playoff runs. Given the strong start to the 2011 Yankee season, all this begs the question: does the Yankees’ strong start to the season augur well for the remainder of the summer? The answer, surprisingly, is not necessarily.

The data in the table below were taken from Baseball Reference. They contain the pre and post All Star game winning percentages of a selection of notable teams between 2007 and 2010.

The data clearly show that at least since 2007, the teams in baseball that have thrived in the post season have turned it on in the second half. With the exception of the 2010 Rangers and the 2007 Red Sox, every team that has won the pennant has been better in the second half than in the first. Furthermore, the 2007 Rockies and the 2010 Giants had unremarkable records before the All Star break, and then broke out after the All Star break while teams like the 2010 Yankees and the 2009 Red Sox were strong at the wrong times, coming out of the gate well but waning as the season wore on.

This means that while records at this point of the season are mostly indicative of where a team will be at the end of the 162 game marathon, the real story will unfold in the second half. The 2009 Yankees had the exact same win percentage, .580, through the first half of the season that the 2011 Yankees had coming into Sunday’s game. That team put itself in a position to be competitive with its first half performance, and then smoked the competition in the later summer months. Red Sox fans no doubt remember how strong their 2009 team began before faltering. Right now the Red Sox and Yankees are the best two teams in the A.L., and the Red Sox have the better record, but the best part of the season has yet to come.