If I was coming up with such a system it would probably be based on wins provided for the team and then I'd probably adjust it to the relative quality of the league and position.  I'd probably call it Shares of Wins Better than Bench or Wins Compared to Replacement Players or something like that.

There are already numerous better systems out there. Slyde was referring to Win Shares above Bench, available at the Hardball Times, and BP's WARP3. VORP, which is the start of warp, at least accounts for position so I'd take it over this.

This just keeps getting funnier. The genius behind this did an espn chat explaining his method. Kudos to this questioner.

Ian, NYC: I don't understand what your point is behind this list. There are people who have put a heck of a lot of science and research into coming up with formulas like this (Win Shares, VORP, etc), while much of what you have selected here is totally arbitrary (why exactly for BA for eaxmple?), and by pretending this is somehow scientific degrades the whole field of work on this subject. Much of what you are including here has been proven to be no reflection on individual player quality (like saves, wins and RBI to a large extent), not to mention penalizing someone because they play on a bad team. Why should anyone take this list seriously?

SportsNation Jeff Bennett: Ian, I think you hit on something. There is no sucjh thing as the perfect way to evaluate a baseball player. Win Shares and VORP are great, but you can ask the same types of questions about their lists. This system is very fluid and puts players in perspective based on where they rank in the majors vs their peers. Nothing more scientific than that.

When in doubt deny all standards. That way at least you're on the same level with everyone else.