WHAT DIFFERENCE DO REFEREES MAKE? The NBA season tips off tonight. I have held off on this post until the beginning of the NBA season. Chris Herring had an article in the Wall Street Journal (June 19) about how NBA teams determine who takes the last shot in a close game. Herring says that: “…at least in the last 10 years, the emphasis is less on the kind of shot that gets taken in these situations than the player who takes it.” The star of a team is expected to take the last shot. Defenses know this and double or triple team the star. Offensive players spread out to leave the star in “isolation”. The offensive strategy at the end of games is apparently known as “hero ball”.
Herring presents two striking statistics. In the NBA, the overall shooting percentage for all shots is 44.8%. For shots in the last 24 seconds of close games, the NBA average is a remarkable 14.8 percentage points lower—29%. Herring attributes the difference to better defense and the ineffectiveness of isolation plays. One other possible explanation is that shots in the last 24 seconds are often subject to a constraint of less than 24 seconds (losing team taking quick shots). Another possible explanation is that referees rarely call fouls in the last 24 seconds. The defense knows this. Some of the 15% gap is what happens when the referees disappear from the game.