Posts Tagged ‘signal and noise’

Randumbness? The new NHL is less predictable than you think

By Colby Cosh - Saturday, February 2, 2013 - 0 Comments

Phil Birnbaum, who along with “Tom Tango” is probably one of Canada’s two great gifts to quantitative analysis in sports, has been studying the NHL over the past few weeks. It was only after a second or third reading of his series breaking down luck versus skill in the NHL standings that I was able to really grasp what he was saying. I’m a fluent speaker of basic stats-ese, but not a native. Phil is a pretty approachable explainer of things (including some of the things devised by Tango), so usually I don’t have to bash myself over the head too hard with his findings. But I didn’t see how interesting the message was until now.

Probably all hockey fans know instinctively that the introduction of the shootout has injected a fair amount of randomness into the year-end NHL standings. Birnbaum, looking at the shootout-era data, has now shown just how much. In the old NHL that still had ties, it took an average of 36 NHL games for a team’s actual talent to become as important to its standings position as sheer randomness. “Talent” is defined here as repeatable ability, ability relevant to prediction: after 36 games, your team’s distance in the standings from .500 would be about half luck and half “talent”, and that would be reflected in your guess as to how they would do in the next 36 games (assuming nothing else about the team had changed). Over a full season, we could be confident that there was little randomness left in the ordering of the teams in the league table.

But in the new post-ties NHL, Birnbaum notes, the standard deviation of standings points has shrunk from about .2 per game to .15. Continue…

From Macleans