The Oklahoma City Thunder's Game 2 victory over the Dallas Mavericks on Thursday produced a striking statistic that seemed to confirm the storyline that the Thunder won largely because point guard Russell Westbrook spent the entire fourth quarter on the bench. With Westbrook on the floor, Oklahoma City was outscored by 12 points. When backup Eric Maynor was in the game, the Thunder held an 18-point advantage over the Mavericks. Simple comparison, right? Not quite.
In the case of a single game, plus/minus is descriptive but not ascriptive. It tells a factual story -- Oklahoma City indisputably played better when Maynor was in the game -- yet is unable to trace those results to an individual player. That is why, as great as it is that plus/minus now appears in online box scores like those on ESPN.com, it must be used with caution.
In fact, in Westbrook's case, plus/minus statistics may not be telling even over a larger sample. According to BasketballValue.com, the Thunder were 8.1 points worse per 100 possessions with Westbrook on the floor this season, the worst net plus/minus among the team's rotation players. Meanwhile, Maynor had the team's second-best net plus/minus at plus-8.2 points per 100 possessions.
However, it would reckless to think that the Thunder are better off with Maynor running the point in place of Westbrook. In fact, there's evidence showing that Westbrook produces much better results than Maynor does with the players who were on the floor with the backup point guard during the fourth quarter of Game 2's win.