Some believe it is better to have loved and lost than to have never loved at all. I say, it's better to have played like an All-Star for a short period and come back down to earth than to have been Yuniesky Betancourt.
Here is a list by position of the top over-performers through one-third of the 2011 season. Some of these are good players who have simply exceeded their own abilities, while others are mediocre players who have far-exceeded their abilities. I'll let you figure out who's who. Call the lesser group the "All-Smoke and Mirrors Team."