Not sure if anybody else has noticed this, but interesting thing about this Canada team I just noticed:
Out of 23 players on this roster, 9 are born in January 2005, 5 are born in February 2005. So, that's over half the roster being born on the first two months of the year. Seems pretty unusual.
Roger Barnsley, a Canadian scholar (and once a colleague of mine 30+ years ago at St. Thomas University in New Brunswick), pioneered research into the Relative Age Effect and ice hockey back in the late-1980s.
If I recall correctly, Roger and his wife were attending an international junior hockey game in western Canada (might have been a WJC game) and they were just casually reading the program. Mrs. Barnsley commented that nearly every player on the Czech team had a January or February birth month, and this simple observation led to Roger building an outstanding academic research career studying the Relative Age Effect.
The upshot? He eventually discovered that in any group of elite hockey players, 50 percent will have been born between January and March, 30 percent between April and June, 15 percent between July and September, and 5 percent between October and December.
One of the easier “quick hacks” to validate Barnsley’s research is this: in what months were the CHL exceptional status players born?
Here’s the answer:
Shane Wright: January 05
Sean Day: January 09
Connor McDavid: January 13
Joe Veleno: January 13
Aaron Ekblad: February 07
Michael Misa: February 16
Connor Bedard: July 17
John Tavares: September 20
It’s a fascinating field of study — there are even research projects that examine how the relative age effect plays out when the school calendar (say, September 01) is used instead of the linear calendar (January 01), and these studies reach the same conclusion: kids born within the first 3 months of the sport entry month achieve greater success.
In the US, a significant (and growing!) number of parents are very aware of the role played by the relative age effect, which has led to “Kindergarten Redshirting,” where parents intentionally hold their kids back from entering the formal school system for an extra year because the children are (statistically) more likely to thrive (academically and athletically) if they are older than their classroom peers.
Anyway, it’s a fascinating area of inquiry.
Edit:
Here’s the 2022 Hilinka-Gretzky birth month breakdown for rostered players (born in the first 3 months [January-March] and also the last 3 months [October-December].
Canada (23 players)
First 3 months: 17 (74%)
Last 3 months: 1 (4%)
Sweden (22 players)
First 3 months: 10 (45%)
Last 3 months: 2 (9%)
Slovakia (25 players)
First 3 months: 12 (48%)
Last 3 months: 4 (16%)
Switzerland (22 players)
First 3 months: 10 (45%)
Last 3 months: 1 (4%)
Czechia (23 players)
First 3 months: 12 (52%)
Last 3 months: 4 (17%)
Finland (22 players)
First 3 months: 12 (55%)
Last 3 months: 3 (14%)
USA (24 players)
First 3 months: 10 (42%)
Last 3 months: 1 (4%)
Germany (25 players)
First 3 months: 8 (32%)
Last 3 months: 4 (16%)
Cumulative Totals:
Total number of players: 186
Born first 3 months: 91 (49%)
Born last 3 months: 20 (11%)
Born in January: 34 (18%)
Born in December: 3 (<2% — all 3 goalies)
For those who believe that “birth year hockey” leads to the loss of talented athletes who, because they are chronologically younger, are weeded out before they have an opportunity to grow and catch up with their older birth year peers, the fact that there is not a single December-born skater in the tournament is powerful evidence in support of the view.