Career Win Shares per 48 minutes — estimated wins contributed per 48 minutes of play. Relative rating normalizes each player 0–100 against the all-time leader.
Win Shares estimates how many of a team's wins each player is individually responsible for, then WS/48 normalizes that to a per-48-minute rate so bench players and stars can be compared fairly.
Originally a Bill James baseball stat, adapted for basketball by Basketball-Reference; splits credit into offensive and defensive win shares.
Rewards defense a bit more than PER does: Bill Russell scored higher on WS/48 than PER in 10 of his 13 seasons (never lower); Bruce Bowen and Tony Allen show the same pattern in nearly every season of their careers.
The GAME model weighs WS/48 slightly more than PER (55/45) specifically because it doesn't separately include DPOY or All-Defense honors elsewhere.
WS/48 feeds into PPP (55% weight) alongside PER — see the PPP page for how the two combine into a single 0-10 grade.