## Bi-statistical

January 15, 2011

Something strange has been happening in the language of sport.  Terminology has been leaking back and forth between hockey and basketball.  The first instance I’ll offer in support of this claim is not just terminology, but a statistic.  Wikipedia claims that ‘plus minus’ (or ‘+/-‘) has been an official hockey stat since ’68-’69, and the Habs were using it in the ‘50s (which of course explains the Stanley Cups) but the NHL has +/- records for the ’67-’68 season, so somebody’s hiding something.

+/- comes to the basketball world via a couple of stats nerds, who were hired back in 2000 by (drum roll) Mark Cuban!  Jeff Sagarin and Wayne Winston turned to +/- as a way of more effectively evaluating players’ overall value, searching for ways to weight the stat, which meant complicating it.  Theirs is not the version which most fans know, which is basically the ‘original’ +/- formulation from the NHL:  you add the points your team gets while you’re playing and subtract the ones the other team gets.  The common NBA calculation is simpler, because it does not involve the complications of special teams that hockey does.

This simple version is found in NBA.com box scores, and comprehensive sites, such as those of ESPN, and Yahoo!, while +/- is not included in less comprehensive box scores like those of Toronto’s newspapers.  Furthermore, it has been mentioned casually during NBA broadcasts for a couple of seasons now.  When I first started hearing it, it always came with an explanation, as in ‘Salmons has 17, but the Bucks are getting outscored by 14 with him on the floor: minus 14!’  During the intermediate period, it would sometimes have sort of truncated or short-hand explanations, or reworked phrasing, as in ‘Salmons has 17, but the Bucks are minus 14 with him!’  +/- is rarely verbally attributed to a team now in that sense, however it has long been applied to ‘units,’ as in ‘The Wildcats are plus nine with this second unit.’

The terms’ adaptation to a new sport should be considered complete with the innovative uses like the later example above.  This also raises questions about its applicability to other sports, like the even more stat-crazy football and baseball.  Indeed, number wonks in both sports are constantly searching for better metrics for overall effect on game play, but that is a topic for several other posts.

The other terms which have crossed over between basketball and hockey seem to have done so differently, and will be discussed here in future posts about ‘the second assist’ and ‘the post.’  The point is, the Dallas Mavericks will win the Stanley Cup before the San Antonio Spurs.  Book it!

PS