I'll start by saying that I could get away with assigning one point to each stat and get a rating system that works for today's game. However, if I want to compare today's players to yesterday's stars I have to modify the system a bit. The reason being is the game has changed so much in 50 years. An assist would be worth more back then as scoring was more difficult. On that you'll have to make your own judgement.
Points Points are points.
Player gets one point for each point scored. Possession Stats Rebounds, steals, turnovers and missed shots . All result in either the giving up or the gaining of a possession. To give these stats a point total we determine the value of a possession. It's not a completely accurate number, but it's pretty close.