Adam Silver really put his foot in his mouth when commenting about NBA officiating last spring.

http://www.espn.com/nba/playoffs/2016/story/_/id/15737936/2016-nba-playoffs-adam-silver-says-reports-show-referees-90-percent-correct

He thought this was a positive spin – refs getting 90% of calls correct is pretty good right?   No!  90% right means 10% wrong and in the NBA with over 1 officiating call per minute, that translates into 50 calls per game and therefore 5 WRONG CALLS on average per game.

Assuming 2/3 of the wrong calls go in favour of the home team (conservative since officials tend to air on the side of caution and not disappointing the loud crowd), that means a net benefit to the home teams of almost 2 calls per game.  2 extra possessions, 2 extra foul calls, etc.   Each possession is worth 1 pt in the NBA, so this is worth 2 pts per game.   Doesn’t seem like a lot?   Home court in the NBA is ‘only’ worth 3.5 pts and home teams win approx 60% of their games.   2 of the 3.5 points of the home edge is conservatively JUST due to a ref bias that Commissioner Adam Silver just inadvertently admitted.

Next time you are watching your team lose a close one on the road due to a bad call, just know that it is a reality accepted by the Commissioner of the NBA.

Last modified: March 18, 2023