In which Dan realizes his true calling: TSN statistician

So after yesterday’s sampling of NHL rosters, I decided to do a little more digging. And to be truer to the group of players that Gladwell used in Outliers I pulled the list of the top 211 draft picks in the 2008 NHL entry draft, courtesy of Of those, 33% were born between January and March. 66% were born between January and June.

More interesting, though, is when I cut that list down to the top 3 rounds of the draft (in other words, the top 91 players drafted): of that group, 43% were born in January, February or March. Under an even distribution you’d expect 25%, so that’s a significant difference.

The more I think about it, the more I think I was looking in the wrong place yesterday. I’d be surprised if NHL rosters were good representations of Gladwell’s hypotheses since developmental factors would be dampened over time by skill, resistance to injury, coaching systems, etc. It’s going to be hard not to waste my next few nights analyzing the last ten draft classes…

So that explains why I never made the NHL

Those of you who’ve read Malcolm Gladwell‘s latest book Outliers know the chapter about hockey players, where he describes the disproportionate number of hockey players with birthdays in the first few months of the year. Gladwell’s theory is that, because of the Jan 1 age cutoff between levels of minor hockey, those born earlier in the year have a size and development advantage over others as they have an extra 6-11 months under their belt. That doesn’t sound like much, but the difference between 6 years old and almost 7 years old is substantial enough that the older players tend to move into accelerated programs, which gives them an advantage. Gladwell then shows several examples of teams whose rosters skew to the early months of the year.

Tonight, after watching my Canadiens blow a late lead, and lose in the shootout to drop the ninth of their last ten on the road, I wondered if their roster followed the same pattern as the elite teams Gladwell described. Based on the 20 players they dressed tonight, here’s how it breaks down:

Jan: 2
Feb: 3
Mar: 1
Apr: 1
May: 2
Jun: 2
Jul: 0
Aug: 2
Sep: 0
Oct: 3
Nov: 2
Dec: 2

That’s 55% in the first half of the year, 45% in the second half. Not exactly overwhelming. Even if I include the other six players who didn’t dress tonight, it’s 58% to 42%. Still nothing to write home about. So I’m faced with three hypotheses:

  1. Gladwell is wrong
  2. Gladwell is right, but my team is an abberation
  3. Gladwell is right, and this explains why my team sucks

So I went looking for more data. My first stop: the Detroit Red Wings, defending Stanley Cup champs and by any measure an elite team. They’re also at 58% born between January and June, the same as Montreal. Then I checked the Boston Bruins, the top team in the NHL this season: also at 58%. Canada’s gold-medal winning major junior team, an all-star team for players in a very specific age range, clocked in at 64%, with 14 of the 22 players born before June 30, but even that isn’t exactly a drastic difference.

Anyway, I know that’s only a sample of four, but I’d prefer to think that hypotheses #1 is correct rather than #3. I’m not holding my breath though.