the stats, obviously, are not mutually exclusive, but you'd prefer the guy who can get on base in ways OTHER than slugging if given the choice. In other words, a guy like Aramis Ramirez is getting on base mostly by slugging (as his .039 IsoD suggests), while someone with a high OBP is getting on base in many more ways that said, I don't know how you could say you would take a 1998 John Olerud over a 1998 Sammy Sosa knowing how their years turned out. You could say "I would prefer a guy with a .447 OBP over one with a .377 OBP in the future", but to say you would want someone whose slightly lower OPS+ resulted in far fewer runs is a little preposterous.