They each have different arm actions, different release point, different breaks on the curve, diff. movement on the FBs, etc. Lilly throws more sliders than Hill and Marshall, Lilly locates his Fb differently than Marshall. Hill has the most deception among the 3 LH'ers. Buehrle relies on a cutter and his change as his out pitches, unlike the other 3. As I mentioned earlier, if a hitter faces some relievers, sleeps the night, goes thru BP, warm-ups, etc. and then faces a pitcher with a diff. arm action, release point, and movement he'll be staring over again as far as depth perception, etc. Right now, you have 3 Lh'ers who have pitched well for the most part, I doubt 4 would be the breaking point espec. one that doesn't have the same pitches as them. So you're basically saying that if a pitcher locates well w/his pitches, creates deception, and keeps hitters off-balance that he will struggle b/c they faced a LH'er the game before. Obviously most series are 3 game series and with the large # of Rh'ed pitchers, except for the 3rd game, it throws that thought process out of whack as far as familiarity. Buehrle would be one of the best pitchers in the NL this year if he was on the Cubs regardless of who the other 4 are. I'd much rather see Buehrle than a less productive RH'ed pitcher.