Personally I think that you have to include 3 things

1. Quality of opp of course...Most important...any fighter worth a half tablespoon of salt can beat guys 10-9 or 22-11 and make a career out of it....You have to beat top contenders as a champion and you have to beat the best available in or around your divisions

2. Longevity....You must have quality wins over a long period of time...A fighter with 2 or 3 wins over top guys in a 2 or so yr time period does not really get the nod for me...we have all seen guys peak and fizzle like the weather changes...You have to be able to prove over a period that you can continue to compete and win at the top level...This is why I hold Bernard Hopkins in such high regard....Sure he has lost some over his past few but fact is he is a top caliber figher who has been a champion almost constantly with the exception of his time between the 2nd Taylor fight and Tarver bout

3. How dominate are the wins.....Guys who squeek out wins by SD or win by KO after the opponent kicked their ass until they faded from stamina issues are not dominate fighters...They are picking the right opp at the right time....EG-- John Ruiz may have been a multi time champion but he won his belts from a faded Holyfield who would have disposed of him easily years before.....Yet Chris Byrd who was no KO puncher by far outboxed his opp convincingly...Making him the more dominate force

This is the way I was taught to decide on how a fighter should be considered in a P4P setting by Bert Sugar and Angelo Dundee...and it is the recipe I continue to keep........Just not sure how some guys justify things like Calzaghe for example being so high after beating Jeff Lacy when Jeff had failed to beat a top quality fighter in their primes...But his win over Jeff no matter how dominate was supposed to make up for all the soft opp.....