I like the idea of it, but I think you will find that if you chart back to 2005, you will find little consistency in your leaguemates habits. The main reason is that the game is in a state of flux when it comes to scoring due to the actual game. For example, I also started a league in 2005 (Keep 3) and the first 4 years I would consistently keep two RBs, and then leave the first or second round with another (we are able to start up to four RBs). At the time, it worked pretty well, but since we give a full point for receptions by TEs (RB/WR is .5) and QBs get 6 points for a TD pass, I had to change my strategy due to the fact that QBs are throwing more now, and TEs are putting up pinball numbers. I still keep my two RBs, BUT two years ago, a very competitive league mate commented to me that he was stunned when at the turn of 1st/2nd I went QB/TE, and actually said it threw him into a tailspin. For me, it really wasn't a conscience decision; I just let the draft come to me and that was where the value was.
I would say chart out the first 8 or so rounds and only go back about 3 years...and even then, use it as a loose guide and not fool proof plan.