The Lions’ last four first-round picks from the past two drafts all have birthdays in January and February. Coincidence? Probably not.

Ndamukong Suh’s birthday is Jan. 6, while Matthew Stafford’s in Feb. 7. Jahvid Best turned 22 on Jan. 30 while Brandon Pettigrew will celebrate on Feb. 23.

Don’t want to tell the Lions how to do their business when it comes to the draft, but ... they might want to look for a first-rounder with a birthday in January or February. Or maybe they’ll do their due dilligence and just coincidentally their top pick, at No. 13, will have a January or February birth date.

It all fits in with the book “The Outliers” by Malcolm Gladwell. It’s a fascinating look at why some people -- like Bill Gates and the Beatles -- achieve so much more success than others. Hard work, at least 10,000 hours of it, is a part of it, but circumstances play a huge role.

One of the early chapters explains why the rosters of Canadian junior hockey teams are heavily tilted toward players with birthdays in January, February and March.

It’s because the Canadian cutoff birthday is Jan.1, and when the little skaters start out in midgets or Timbits, those kids are more physically mature and able to compete better because they’re older. So as they move along, they earn spots on top teams, draw the better coaches and the chance to continue to move upward. Gladwell presents the rosters of the two teams in the 2007 Memorial Cup as evidence and it’s amazing.

It’s got to be the similar in the NFL. Generally kids born in January and February are the oldest in their class. It means everything physically and mentally.

So birth date can play a role in the success of an athlete. The author used hockey as an example, but perhaps it applies to the NFL too.

Lions coach Jim Schwartz has read the book, I heard him recommend it during a speech at a caddies banquet at Oakland Hills. So maybe he’s onto this. Maybe that’s why his top picks have birthdays in January and February.

Perhaps Matt Millen never read it and that’s why of the eight first-round picks he made only one had a birthday earlier than May. That was wide receiver Mike Williams (Jan. 4).

Evidence? Here we go: Joey Harrington (Oct. 21), Ernie Sims (Dec. 23), Charles Rogers (May 23), Roy Williams (Dec. 20), Gosder Cherilus (June 28).

The only exception is Calvin Johnson whose birthday is Sept. 25. No good explanation other than he’s off the charts -- quite literally.

So there you go. Now we have another reason to add to the list of why Millen struggled with the draft. He paid no attention to birth dates.

(Paula Pasche covers the Lions. Follow her on Twitter @PaulaPasche. Read her Lions Lowdown blog at oplions.blogspot.com.)