You may be a great performer on your own. But how much do you help your team? The metric de jour of the NBA - the plus-minus statistic - goes beyond so-called "glory statistics" like points or rebounds to measure a player's total contribution to victory. Refined by Dan Rosenbaum, an economist at UNC Greensboro, plus-minus measures how many additional points a team scores when a given player is on the floor. In Measuring How NBA Players Help Their Teams Win, he says that plus-minus statistics measure "how point differentials change when a particular player is in the game versus when he is not." Subtracting individual points scored from the point differential isolates the contribution due to teamwork.
For instance, the threat of a three-point shooter may cause the other team to spread its defense and allow someone else to score. Nobody gets credit for a three-point shot, since it didn't happen. But the plus-minus statistic should capture the extra points made possible by the mere threat of the three-pointer.
We reward glory in sports, business and life. We tend not to measure teamwork, which is less tangible and harder to capture. What's the plus-minus of a company's marketing department? Of its legal counsel? Hard to answer, but worth asking.