noleaniml-I first got the idea from bhazelwood's gdreports in Gridiron Dynasty. But then seble posted a thread about how he was going to create a way for each coach to create their own custom formula, by weighting each attribute so that coaches that prefered ATH and DEF and disregarded DUR, could get a Overall Rating for a player that more closely related to the player's actual abilities than the Total Rating that we are given now. I bumped the thread in the main forum, and hyperlinked to it here so you can see what I'm talking about:
http://www.whatifsports.com/forums/Posts.aspx?ForumID=30&TopicID=433659&ThreadID=9335303#l_9335303
I've been using that type of system for a few years now, and as I was doing the MWC previews, I put together a spreadsheet so that I could figure out the Adjusted Overall Ratings, I'd been using on my own players, for every MWC player on every team. Then I realized that I could use the exact same spreadsheet (12 spaces for players fits nicely with 12 team conferences) and just copy and paste in the "Team Ratings" stuff for each team and the spreadsheet then gives me a weighted overall score. I use three different forumlas, get three different weighted scores, add the three together, include small formula that adjusts for teams that don't have 12 players (as in pre-recruiting), and come up with the SRP for each team. The conference teams are all added, and then divided by 12 to give the conference score. Now that I've got the fields and formula's set up, it doesn't take that long to come up with the SRPI.
It doesn't take into account IQs or FT grade. Also if a team has walkons it can really hurt their score because they are calculated along with everyone else, which when I have walkons, I never play them a single minute, and as long as I have 10 players it doesn't really matter.
Basically the point is to give every team the next step past the overall "Team Rating" that you can get, by adjusting that overall "Team Rating" to more accurately reflect the talent level of your team. Does that mean you'll always win teams rated higher than you? No. But like RPI it gives you a better idea of where you stand than simply comparing your unadjusted Team Rating to your conference mates.
Unfortunately I don't have anything beyond the MWC for previous seasons.
Hope that helps.