Is the NHL drafting the wrong players because of a hockey birthday bias?

TORONTO – Sidney Crosby. John Tavares. Henrik Zetterberg.

These hockey heavyweights all have a few things in common: they’re born later in the year but are top NHL point leaders, a contradiction to a ‘birthday bias’ that exists in sports.

A new study looking at Canadian hockey players drafted into the NHL over the course of nearly three decades suggests that while the birthday bias exists, it doesn’t accurately predict talent or success. Turns out, players born later in the year end up scoring more points and playing more minutes on the ice compared to their counterparts born earlier in the year.

“There’s no doubt that drafting professional athletes is an inexact science. Plenty of sure-fire first-round picks fizzle while some late-round picks unexpectedly become stars. But our results show that, at least since 1980, NHL teams have been consistently fooled by players’ birthday…,” said Dr. Robert Deaner, lead researcher in the study.

“They greatly underestimate the promise of players born in the second half of the year, the ones who have always been relatively younger than their peers. For any given draft slot, relatively younger players are about twice as likely to be successful,” he said.

Deaner is a professor at Grand Valley State University in Michigan.

All Canadian-born skaters drafted into NHL included in study

Deaner and his team studied all Canadian-born skaters drafted into the NHL between 1980 and 2006 for their study. There were over 2,700 in total – half played at least a game while another quarter played at least 200 career games, or three to six seasons.

At first, Deaner meant to look into aggression in NHL players, but after reading popular journalist Malcolm Gladwell’s take on relative age effects in his novel Outliers, Deaner studied birth month and aggression.

Instead, he noticed a relationship between birth month and career length.

Results showed that on average, NHL draft picks born between July and December are much more likely than those born in January, February or March, to have successful careers.

Those born in the first three months of the year make up 36 per cent of all draftees, but they only played 28 per cent of games and only scored 25 per cent of the points.

On the other hand, players born in the last few months of the year played 42 per cent of the games and scored 44 per cent of points accumulated by those studied.

Birthday bias, underdog effect at play in hockey

Previous research has already pointed to this birthday bias, in which athletes on the older end of their age group are more likely to get picked.

In elite Canadian youth ice hockey – the CHL or the CJHL – about 40 per cent of players are born in the first three months of the year while only 15 per cent are born in the last three months, for example.

This bias starts early on in an athlete’s career, from special coaching time to more opportunities to be seen by key scouts.

“One possibility is that relatively young players are less likely to play in the top junior leagues, and the NHL teams generally prefer to draft from the top leagues,” Deaner told Global News.

The boys born earlier in the year may be taller and slightly more experienced than their counterparts, giving them an edge.

Still, that leaves the younger players with a knack for fighting harder to get noticed and to catch up with their peers.

“It’s called an underdog effect. This would involve relatively younger individuals developing better work habits so that they improve their skills more in adulthood,” Deaner explained.

“The idea is that they’ve always had to find a way to make it against older, larger players.”

Right now, it’s unclear if this effect exists in sports but it’s been studied in academics.

Birthday bias starts early on

Andrew Mercer, an Ottawa-based goalie coach who’s trained players for about 15 years, says he sees younger players foster these hardworking habits early on.

“As you’re growing up you’re constantly playing against those players born later in the year,” Mercer said.

He’s owner of Andrew Mercer Hockey Development, a year-round, full-time goalie training school.

“You see this effect right in front of you,” he explained.

Players born earlier in the year are more physically developed, and because they’ve had a history of getting more ice-time or opportunities from coaches, they have a fleshed out resume.

“NHL teams are looking at your midget stats and what you’ve done throughout and they’ll see this person has done quite well and he’s a good size,” he said.

“In drafting, they’ll try to do projections of what the player will turn into in a number of years but you have to take the best player available. That’s why I think those players go earlier in the draft or get drafted in the first place.”

Meanwhile, the younger players stick it out in smaller leagues. But they’re working hard to catch up, and because they’re a bigger fish in a smaller pond, they get more time to hone their skills.

Deaner focused his study on Canadian players because in Canadian youth ice hockey, there is a Jan. 1 cut-off date – players born later in the year would have been consistently younger than their age group.

But the bias isn’t unique to Canadian players, he said, noting that it’s the same in drafting players from most European countries.

Deaner says his next steps are to explore if NHL teams generally prefer to draft from the top leagues, excluding players in smaller pools.

His complete findings were published Wednesday in the journal Public Library of Science or PLoS ONE.

carmen.chai@globalnews.ca
Follow @Carmen_Chai//