This is a tough question to answer. The fact is that your typical fantasy league is going to value stats that have little predictive or descriptive value such as RBI. I think that the BE score would be a good metric for how valuable a player has been in one of these kind of fantasy leagues in the past. However, if you're wanting the BE score to be predictive of future value to a fantasy team, what you're really trying to project is future performance in general. If you want to get into that, the inputs that you have aren't sufficiently predictive and you're going to have to lean on more advanced metrics. As far as I can tell, BE weights all of the 7 stats exactly equally. The truth is that RBI is a terrible stat and VORP is an okay stat, for instance.
There are some really smart people out there working on projection systems that you could look into. Dan Szymborski does ZiPS, Tom Tango does Marcel and then you probably know about Bill James who has a projection system by the same name. There are others, but these are probably the most popular.
I'd love to offer my assistance; baseball nerdery plus development nerdery would essentially be my dream job, but I would be way too swamped until June or so to be able to contribute. I don't know how SABR savvy you are, but my contact is in my profile and you're welcome to bounce questions off of me. There are also tons of resources out there I can direct you to.
There are some really smart people out there working on projection systems that you could look into. Dan Szymborski does ZiPS, Tom Tango does Marcel and then you probably know about Bill James who has a projection system by the same name. There are others, but these are probably the most popular.
I'd love to offer my assistance; baseball nerdery plus development nerdery would essentially be my dream job, but I would be way too swamped until June or so to be able to contribute. I don't know how SABR savvy you are, but my contact is in my profile and you're welcome to bounce questions off of me. There are also tons of resources out there I can direct you to.