Win Shares is an advanced player statistic in basketball that attempts to divvy up credit for team success to the individual players on the team.
It is not specifically used for NBA betting picks, but rather understanding how a player’s contribution to their team’s success can influence betting decisions indirectly by providing insights into player and team performance.
Check out the players with the highest Win Shares in NBA history.
Origin of Win Shares
The idea of Win Shares was first developed by Bill James, a noted baseball historian and statistician, for the sport of baseball, and was adapted for basketball by basketball statistician Dean Oliver.
The adaptation for basketball is detailed in his book, “Basketball on Paper.” The intention was to build a unified measure that encapsulates a player’s offensive and defensive contributions into a single statistic.
The Formula of Win Shares
Calculating Win Shares is a multi-step process that involves several statistics.
Here is an overview of the steps:
- Estimate Team Performance:
- Calculate the team’s offensive rating (points produced per 100 possessions) and defensive rating (points allowed per 100 possessions).
- Calculate Marginal Offense and Marginal Defense:
- Marginal Offense = Points Produced by the player – 0.92 × League average points per possession × Player’s offensive possessions.
- Marginal Defense = Player’s counterpart points allowed – 0.92 × League average points per possession × Defensive possessions attributed to the player.
- Calculate Marginal Win Score:
- Marginal Win Score = Marginal Offense + Marginal Defense.
- Convert Marginal Win Score to Win Shares:
- Win Shares = Marginal Win Score ÷ Wins Produced per Win Share.
- Wins Produced per Win Share is a scaling factor derived from the team’s overall efficiency.
Example of Win Shares in Practice
Let’s consider a simplified example involving a fictional NBA player.
Suppose the player contributed 300 points over the course of the season, and the league average was 1 point per possession with an average of 100 possessions per game over 82 games.
Step 1: Calculate Player’s Offensive Possessions
- Assume the player had 250 offensive possessions.
Step 2: Estimate Marginal Offense
- League Points Per Possession = 1
- Points Produced by Player = 300
- Marginal Offense = 300 – (0.92 × 1 × 250) = 300 – 230 = 70
Step 3: Estimate Defensive Contribution
- Assume the player’s counterparts scored 240 points against him.
- Marginal Defense = 240 – (0.92 × 1 × 250) = 240 – 230 = 10
Step 4: Calculate Marginal Win Score
- Marginal Win Score = 70 + 10 = 80
Step 5: Convert to Win Shares (Assuming 10 Wins Produced per Win Share)
- Win Shares = 80 ÷ 10 = 8 Win Shares
This means the player was worth approximately 8 wins to his team, based on his offensive and defensive contributions.
Win Shares – Not Just Another Advanced Metric
Win Shares is a comprehensive metric used to evaluate the overall impact of a basketball player on their team’s success.
It integrates various aspects of a player’s performance into a single statistic that approximates the number of wins contributed by the player.
While initially developed for analytical and team management purposes, understanding Win Shares can help bettors and analysts assess the value of players more holistically, which can indirectly influence betting strategies by highlighting under- or overvalued players in terms of their contribution to winning games.
Check out some more advanced NBA metrics including Player Efficiency Rating, Usage Rate and True Shooting Percentage.
