Wins Produced is a metric developed by David Berri, Martin Schmidt, and Stacey Brook to measure how any given player's individual contributions relate to winning basketball games. It is documented quite thoroughly in the book The Wages of Wins and further on The Wages of Wins blog, The Wages of Wins Journal, (as well as the many blogs in the Wages of Wins Network such as and Arturo's Silly Stats and others). You can see the formula for calculating wins produced here. Any attempt to summarize the book in just a paragraph won't due it justice (seriously, read the book!) but the primary factors that influence wins produced are, in order of importance: Shooting Efficiency (both from the field and from the free throw line), factors that involve gaining and keeping possession of the ball (rebounds, steals, and turnovers), and team factors (assists, blocks, and personal fouls).
Unlike other all-in-one metrics such as John Hollinger's PER and the NBA's Player Efficiency, which reward players for all shot attempts, Wins Produced treats missed field goal attempts as a negative factor. Here's an explanatory excerpt of this latter effect from the Wages of Wins FAQ:
NBA Efficiency = PTS + ORB + DRB + STL + BLK + AST – TO – All Missed Shots
Game Score = PTS + 0.4 * FGM – 0.7 * FGA – 0.4*(FTA – FTM) + 0.7 * ORB + 0.3 * DRB + STL + 0.7 * AST + 0.7 * BLK – 0.4 * PF – TO
These measures all align because each tells a similar story about player scoring. For example, imagine a player who takes twelve shots from two-point range. If he makes four shots, his NBA Efficiency will rise by eight. The eight misses, though, will cause his value to decline by eight. So a player breaks-even with respect to NBA Efficiency by converting on 33% of his shots from two-point range. From three-point range, a player only needs to makes 25% of his shots to break-even.
Most NBA players can exceed these thresholds. Therefore, the more shots most NBA players take the higher will be his NBA Efficiency total. As a consequence, players who take a large number of shots tend to dominate the player rankings produced by this measure.
The above is one of the reasons that we are so adamant that one must look beyond scoring totals to measure a player's offensive efficiency.