I think you have to look at each player individually. Mark Teixeira and Adam LaRoche are notoriously slow starters, but I wouldn't call their Aprils and Mays "slumps" -- that's just how they play year in and year out. Some players might be able to snap out of their slumps faster if they were willing to pull their heads out of their butts, get out of their routines, and try something different. You know, if your feet hurt, maybe you don't
need to wear four pairs of socks, that sort of thing.
Then there's Jeff Francoeur, as mentioned in the poll. He's just special. There are players who seem to be in a career slump here, but do great with a change of scenery, like we see KJ doing so far in Arizona. I just think everyone needs to be measured individually.