To be one of the top footballers, it takes more than just skill. As peculiar as it may sound, it also makes a difference when you’re born.

Take, for example, the eleven Manchester United players who started against Chelsea on January 11, 2009: Edwin van der Sar, Gary Neville, Nemanja Vidic, Jonny Evans, Patrice Evra, Cristiano Ronaldo, Ryan Giggs, Darren Fletcher, Ji-Sung Park, Dimitar Berbatov and Wayne Rooney.

Other than all being excellent professional footballers, they have something else in common. Incredibly, nearly all of them were born around the same time of the year. Consider that:

• Ten of the eleven players (91%) were born in October, November, January or February (Patrice Evra is the exception; he was born in May).
• Six of those ten were born in either January or February.
• Four of those six were born in February (Neville, Fletcher, Ronaldo and Park), and
• Of the six born in January or February, three of them have birthdays in the same week (Dimitar Berbatov, January 30; Darren Fletcher, February 1; and Cristiano Ronaldo, February 5).
• Fifty four percent of the starting eleven were born in January or February, and
• Ninety percent of the Man United players were born between October and February.

The similarity in the birthdays is even more pronounced when, instead of reading the names of the starting eleven, you see what their birthdays are:

• October 29
• February 18
• January 2
• October 21
• February 1
• November 29
• February 5
• February 25
• May 15
• January 30
• October 24

And who were the goalscorers in this 3-0 victory against Chelsea? None other than October 21 (Vidic), October 24 (Rooney) and January 30 (Berbatov).

And what about fellow Manchester United players? Wes Brown, born October 13. Rio Ferdinand, November 7. Paul Scholes, November 16. Nani, November 17. Owen Hargreaves, January 20. Carlos Tevez, February 5.

So, is this all just a coincidence?

Certainly not according to author Malcolm Gladwell in Outliers, one of the most eye-opening books released in the past twelve months. While Gladwell doesn’t mention the Manchester United example in his book (the United example above is compiled by research done by me), Gladwell argues in his book that when you’re born has a profound impact on how successful you can be.

It has nothing to do with astrology or that people born in the winter months are luckier than others. It’s simply that the eligibility cutoff for soccer in Europe is often September 1. That means that if you turned age 10 on September 2nd, you’d be playing with some boys that don’t turn 10 years old until the end of August. That sort of advantage constitutes an enormous difference in physical and mental maturity.

Hence, players born between October and February would have a huge advantage over players born between March and August. They’d be more likely to play more often at such a critical age, and be more likely to make it into professional leagues.

Gladwell found that in the Premier League at one point in the 1990′s, there were 288 players born between September and November, and only 136 born between June and August.

What is an outlier? It’s a scientific term to describe things or phenomena that lie outside normal experience. Gladwell spends the entire book describing stories of outliers — men and women who, for one reason or another, are so accomplished and so extraordinary and so outside of ordinary experience.

Now you see how Manchester United are outliers.

Malcolm Gladwell’s book, Outliers: The Story of Success, is available from Amazon. Outliers: The Story of Success [AUDIOBOOK] [UNABRIDGED] is also available as an audiobook, which is highly recommended.