Monday, 4 March 2013

The Age-Old Age Question

There are always questions when it comes to teams keeping their young players on their rosters rather than returning them to their respective junior clubs. If the player is off to a hot start like Jeff Skinner was back in 2010-11, he's giving you every reason not to send him back. From a management point-of-view, you'd like to have this problem season after season, so the scouting departments of each NHL team weigh all sorts of factors about a player's potential career. But what if it was as easy as knowing what month in which your potential draft pick was born?

Three men set out to determine if there was a direct correlation between birth date and scoring, and their findings were actually quite surprising. Dr. Robert O. Deaner and Dr. Aaron Lowen of Grand Valley State University, and Dr. Stephen Cobley of the University of Sydney - three psychology professors - decided to look at a vast amount of data about NHL players to see if a player's birth date factored into the success he saw at the NHL level.

We've heard the long-held belief that players born early in the year have a better shot at making the NHL because they are normally bigger and more physically-developed based upon the added time they've had to grow and mature compared to players born late in the year. While NHL teams would never subscribe to this sort of thinking out loud, this belief seems to be in full-force at NHL drafts according to the research done by the doctors above and published in PLOS One.

According to an excellent article by Beth Carter on Wired.com, the doctors found some interesting statistics from all players drafted between 1980 and 2006.

They found that, on average, NHL draftees born between July and December comprised 34 percent of those drafted, but played in 42 percent of the games and scored 44 percent of the points. On the other hand, those born in the first three months of the same year comprised 36 percent of drafted players but played in just 28 percent of games and scored 25 percent of the points.

The researchers focused on Canadian players because Canadian youth leagues assign players by age, with a December 31 cut-off date. That makes it easier to compare players who are the same age but were born at different times of the year.
For all that the NHL tells us about how they look for the best players, it appears that they are drafted based upon when a player was born rather than the overall talent. When there are more players drafted who were born in January, February, and March than there were in the last six months of the year, that could just be coincidence, but it could also be a more subconscious drafting method.

There are factors, as Dr. Deaner concedes, that come into play in a number of situations, but the overall trend in the data is overwhelmingly conclusive in pointing out that young players have longer careers.
Deaner concedes drafting athletes is an inexact science and myriad factors come into play, but the evidence suggests NHL teams have been "consistently fooled by players' birthdays or something associated with them." He's at a loss to explain just what is behind the selection bias, which occurs when someone — say, a coach — grants fewer opportunities to relatively younger players than might be warranted by their talent.
But there are some flaws in the study that are pointed out by TSN analyst and former NHL executive Craig Button. Button looked over the information, and found that just focusing on Canadians and non-goaltenders narrows the criteria field significantly.

"The scouts watch games by the thousands and they are looking at so many different aspects of a player," Button told Miss Carter. "What
aspects of a player's skill set are weighted more greatly when assessing players and then ultimately selecting them? What of those skills and aspects could be affected by age would seem to me to be a plausible question."

Indeed, there are some things to consider at that age. These are seventeen and eighteen year-old boys, and their maturation will be all over the map. However, it is plausible to suggest that children born in January would be more physically mature than children born in December. There will be those younger children who simply reach puberty first, but those children would be the exception rather than the norm. Therefore, it would be safe to say that drafting a player born in January would return results faster as that player would be closer to being physically mature than players born later in the year.
Deaner and his team admit they don't yet fully understand the selection bias they've uncovered, though Deaner has a few ideas about what might be going on. Like Button, he acknowledges that being a few months older can give a child the appearance of a physical advantage (something the Freakonomics piece suggested)– in this case making them more likely to be selected for the elite youth teams and, later, in the pro draft. Another theory is that the younger kids might be performing better in the long run because of the underdog effect, in which they work harder to overcome any obstacles, real or perceived, to their success.
So what does it all mean? Well, it just means that NHL teams are still drafting players born early in the year over players born later. There's no scientific proof at this time that drafting players born in the last quarter of the year is any better than drafting a player born in January except when it comes to career games played.
Since teams care more about point production than they do about career games in the grand scheme, there's no guarantee that these late-bloomers will be high-scorers with long careers. For every Joe Nieuwendyk (September 10, 1966), there's a Wayne Gretzky (January 26, 1961) who has outscored everyone with just assists. What the information discovered by the three doctors has presented is that there is still a lot of analysis to be done on any sort of trend in the NHL, and that someone somewhere will get paid well once they have broken the code and provided NHL teams a better way to evaluate talent.

Until next time, keep your sticks on the ice!

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