Fantasy Baseball: Who Do I Keep?

I can keep 4 players in a pts based fantasy baseball league. This league is only pts, no roto categories. I can keep any combo of hitters/pitchers. I think in the redraft, pitchers will go fast so I'm wondering if I need to keep a pitcher even though my hitters produce more points. The players I am definitely going to keep are: Prince Fielder, Ryan Braun, and Grady Sizemore. I need to keep one more from this group of players: Chris Young (the pitcher), Adam Dunn, Brian Roberts, Carlos Pena, and James Shields. If pitchers go early and often in the redraft (ie starting with round 5), does that mean I need to keep a pitcher (i.e. Chris Young) or do I keep the player who produces the most points (ie Brian Roberts or Adam Dunn). I am really wrestling with this one and any help would be most appreicated.