If April is the month of churning through sleeper candidates to figure out who can stick on your roster, May is the month where you start to look at disappointing performers to see if it's a simple slump or something more. There are still plenty of intriguing players on most waiver wires, but the fact that they're still there after a month of games is a strong indication that they aren't as good as they look at first glance. Spencer Turnbull of the Tigers illustrates this nicely.More importantly[...]