The Chicken/Egg Paradox

There’s a great article in the Edmonton Journal today about biased refereeing. After looking at more than 2300 power-plays, the Journal and a Vancouver-based researcher discovered that the home team had 11.5% more power-play advantages than the road team.

Curtis Stock, who wrote the article, did a good job getting quotes from different sources. Flames head coach Mike Keenan and Dr. Patrick Keelan, a Calgary-based psychologist, both felt that the referees were being influenced by noise from the crowd.

Stephen Walkom, the NHL’s director of officiating, unsurprisingly disagreed. To quote him exactly:

I think both parties are a little off here. Here’s my personal theory:

1. A team is more likely to be penalized when they’re at a competitive disadvantage – whether that’s being stuck in their own zone, playing against opponents with a higher talent level, playing against more rested opponents, whatever.
2. The NHL systematically slants their schedule in favour of the home team – Tyler over at mc79hockey.com had a great post on this (though I can’t seem to find it at the moment) which conclusively showed that the overwhelming majority of teams playing their second game in two nights were visitors.
3. The NHL has subtle rules that benefit the home team – most notably, last change. This means that unless the visiting coach is willing to jump through hoops, the home team coach gets his preferred matchup.
4. Because the home team has systematic advantages built in, the visiting team is more likely to take a penalty because they are more likely to be at a competitive disadvantage.

In other words, I think that the (roughly) 55%/45% penalty differential in favour of the home team is more likely a result of the (roughly) 55%/45% win record than a cause of it. Let’s open it up though – what do you think?