Fans do impact the game
Going into last night’s game against the Heat, I projected the Spurs as slight favorites. Honestly, I didn’t think they were a better team than the Heat given their expected roster, but the impact of home court and the back to back the Heat were completing was just enough for me to consider the Spurs more likely to win.
Clearly there were a few stunning events that made my doubts appear trivial. Tony Parker’s appearance from nowhere clearly made a huge difference and, of course, Matt Bonner was simply unreal. Clearly a 30 point win is a pretty good indication that the Spurs are capable of doing just fine without the benefit of home court, but recent data presented at the MIT Sloan Sports Analytics Conference reminded me of the importance fans can play on their team’s chances.
I wrote a post on the causes of home court advantage in one of my first blogs on basketball-analysis.com. In the end I conclude that home attendance is a highly correlated with home court advantage, even after accounting for team strength.
In my article, I suspected that referee bias was a significant contributor to this effect, but I shied away from making such an outright statement because there wasn’t quite enough information to be conclusive regarding this controversial issue in basketball. However, the presentation “The Real Reasons Behind the Home Field Advantage” (presented by Toby Moskowitz) went a bit further and included many other sports. The most conclusive example in my mind was the example in soccer relating to injury time.
In soccer matches in which the home team was winning by 1 goal, injury time averaged about 2 minutes. However, this time was nearly doubled when the home team was losing by 1 goal. The reason this observation is most appropriate is because injury time is considered almost completely subjective. In all other sports, the consistent pattern was that objective calls were effectively even and subjective calls were biased for the home team, especially in the game’s most crucial moments. In basketball, the examples used compared difficult calls such as traveling to easy calls such as shot clock violations. Although I considered this, I couldn’t conclude based on a couple subjective tendencies if these were caused by referee bias or a pumped up home team.
Neither Toby nor I suggested corruption as a likely contributing factor in referee bias. The assumption was rather that referees were more likely to be influenced to favor the home team. The most obvious example might be that a fan reaction catches the referee’s attention and he makes a call that he would not have noticed for the road team.
The biggest conclusion to me is that fan involvement does seem to matter (theoretically more for bigger games) so get pumped and support the team, because it could make a difference.