Outliers has two parts: "Part One: Opportunity" contains five chapters, and "Part Two: Legacy" has four. The book also contains an Introduction and Epilogue. Focusing on outliers, defined by Gladwell as people who do not fit into our normal understanding of achievement, Outliers deals with exceptional people, especially those who are smart, rich, and successful, and those who operate at the extreme outer edge of what is statistically plausible. The book offers examples that include the musical ensemble The Beatles, Microsoft's co-founder Bill Gates, and the theoretical physicist J. Robert Oppenheimer. In the introduction, Gladwell lays out the purpose of Outliers: "It's not enough to ask what successful people are like. It is only by asking where they are from that we can unravel the logic behind who succeeds and who doesn't." Throughout the publication, he discusses how family, culture, and friendship each play a role in an individual's success, and he constantly asks whether successful people deserve the praise that we give them.The book begins with the observation that a disproportionate number of elite Canadian hockey players are born in the first few months of the calendar year. The reason is that since youth hockey leagues determine eligibility by calendar year, children born on January 1 play in the same league as those born on December 31 in the same year. Because children born earlier in the year are bigger and more mature than their younger competitors, and they are often identified as better athletes, this leads to extra coaching and a higher likelihood of being selected for elite hockey leagues. This phenomenon in which "the rich get richer and the poor get poorer" is dubbed "accumulative advantage" by Gladwell, while sociologist Robert K. Merton calls it "the Matthew Effect", named after a biblical verse in the Gospel of Matthew: "For unto everyone that hath shall be given, and he shall have abundance. But from him that hath not shall be taken away even that which he hath." Outliers asserts that success depends on the idiosyncrasies of the selection process used to identify talent just as much as it does on the athletes' natural abilities.