Following on from the first installment of our NBA Advanced Stats Series (which explained PER), it’s time to look at something that sounds complex but is actually fairly straightforward – Win Shares.
What’s a Win Share?
In it’s most basic terms, a win share calculates a single player’s contribution to their team’s win total.
It’s formed using player, team and league-wide statistics. So, if you add up all the players’ win shares on a team, it will roughly equal the team’s win total for the season.
A player generates offensive and defensive win shares. An offensive win share is calculated through a player’s points produced and offensive possessions and dividing it by marginal points per win.
Defensive win shares are formed by taking a player’s defensive rating and dividing it by the marginal points per win.
Add offensive and defensive win shares together and voila: a player’s total win shares.
Why Win Shares Matter
Many analysts prefer win shares over PER because it measure’s a player’s value based on wins, and it values both the offensive and defensive output of a player equally.
Additionally, win shares values playing time – some players who barely play in the league might have a higher PER than superstars, but those stars could have double the win shares (thus proving their importance to the team).
For example: In 2013, Marc Gasol and Mike Conley of the Memphis Grizzlies ranked sixth and 11th among all players with 11.5 and 9.9 win shares respectively. These two weren’t the best players in the league, nor did they post monster numbers, but their high win share total does indicate they were vital to the Grizzlies winning games.
To find out more information on win shares throughout the season, check out Basketball-Reference.
