So i try to draft low whip low oav pitchers. I use some cookies, & at other times not. My question is why don't these picks ever come close to past performance? I play my teams in parks like fulton county, fenway, coors, & yankee stadiums. I can see some uptick in era and such being a bit higher, but guys that have a large sample size with performance histories showing era under 3.00 shouldnt consistantly be getting 6.00 & higher in my opinion. Am I doing something wrong???

1.) What cap are you playing?  Performance histories ONLY consider performance in OLs (80M) cap and provide no guidance at all for higher caps.
2.) Why are you using such high offense parks?  The combination of high cap and high-offense park means all pitchers will post much higher numbers than usual.
3.) Do you know how to set pitch counts?  If not, in-game fatigue could be contributing to your pitcher performance.  Lots of good threads on this if you need help.

4.) Do you draft players with good defensive ratings? Do you ever play people out of position?

Your 3 current teams are all in high caps.  Like contrarian said, Performance History counts ONLY Open League performance and is no indicator of what to expect at higher caps. 

& please don't forget one of the SIM basics that applies especially in the higher cap leagues. The lineups your staff faces is loaded from 1-8 with highly productive, "all star and half of fame" type hitters. Would also reiterate contrarian's point regarding in-game fatigue. Be sure your not using guys who had RL figures of 1 IP per game for 30 or 35 pitches. My starting rule of thumb when setting pitch counts is to use 15.5 pitches per RL ip (e.g. a guy who threw 1.23 ip/9 in RL would be set for for 15 target/20 max PC). Again, a rule of thumb which I often tweak as the season rolls along.

Just some food for thought.