Top ERA (Starters), 2011 1. A's: 2.56
2. Mariners: 3.14
3. Giants: 3.16
The A's have the lowest team ERA despite having the 19th best bullpen ERA because their starting pitching is so much better than any other team. They might have trouble keeping up this prodigous pace, though, because Dallas Braden and Brandon McCarthy are both on the DL. That means that two of the current spots in the rotation go to Guillermo Moscaso (1 career start) and Josh Outman (missed 2010 with Tommy John surgery).
The top of their rotation is extremely good, but they will probably come back to earth too (Trevor Cahill, 2.02; Gio Gonzalez, 2.20; Brett Anderson, 2.84). The A's are 3 games under .500, but only 2.5 games out because no one is running away with the AL West. If they keep this up all year (a big if), it could be the most impressive performance for a starting rotation since the Maddux-Glavine-Smoltz Braves in the 1990's.