Today is Berkshire Hathaway chairman and CEO Warren Buffett's birthday. He is 88, but the best birthday present he ever received came long ago, before he made his first penny — before he was even born. It didn't come wrapped; it doesn't even take a physical form. It's called luck. Of course Buffett's made a lot of money — for those who like playing around with numbers, like Buffett does, his fortune works out to millions of dollars per each day of his life. But even some of Berkshire Hathaway's most recent big bets paying off, led by Apple, Berkshire is trailing the the S&P 500 this year. Not a year goes by that people, including Buffett himself, don't comment on how much harder it is for him to keep up his long-term lucky streak against the index. (His estate plan for his wife is to have her invest 90 percent of her money in the S&P 500 and 10 percent in government bonds.) The billionaire investor's long-term approach to the markets, shrewdness when it comes to valuing stocks and businesses, and temperament, are a unique skill set that Buffett has used to his advantage. He said in an HBO documentary about his life that he looked back with more sentimentality on old Moody's tomes on securities than family artifacts, which suggests something in his makeup was probably made for picking stocks. But luck, or winning the "ovarian lottery," as Buffett called it, has been an instrumental factor in building his billionaire fortune. And luck doesn't get the recognition it deserves as a success factor. Analysis of the traits of billionaires and the effort to uncover their secret to success tend to go granular: Do they awake at 4 a.m.? Do they write handwritten notes from their CEO desk to everyone, even the little people? Or does success tend to circle around some new (and not necessarily improved) versions of habits already covered by the likes of Stephen Covey? Some billionaires feel the need to write treatises on what has made their success unique — such as hedge fund legend Ray Dalio's recent "Principles" or the Koch brothers philosophy of market-based management detailed in "The Science of Success." Buffett has written a lot through annual letters to shareholders over the years on the right ways to invest, but he has never attempted to sum it all up in a easy-to-read self-help guide to success. That may be one reason why Twitter users were so easily fooled this week into thinking a series of fake Buffett tweets on lessons to live by were really from Buffett. (He told CNBC on Thursday that he has better things to do than tweet.)

Luck's role in success

Many successes start with luck. "Having the good luck to win the 'ovarian lottery' is a major determinant in success in life in general — and in business in particular," Professor David Kass told CNBC. The clinical professor of finance for the Robert H. Smith School of Business at the University of Maryland was the first to publish the Buffett "ovarian lottery" comments, based on notes he took at a 2013 graduate student event where Buffett spoke. Luck may seem like the least tangible, least controllable success factor. After all, what can one do about luck? But there's a perfect example from Buffett's business history that Kass shared with CNBC, showing how those who believe in luck are also on the lookout for luck when it delivers an opportunity into their lap: When Buffett was a 20-year-old MBA student at Columbia University, he learned that the investor who was his role model and hero, Professor Benjamin Graham, was the Chairman of the Board of GEICO. Since Buffett was interested in anything that Graham was interested in, he took a train to Washington from New York (1950), arriving on a Saturday morning. Without calling or writing ahead of time, Buffett was very lucky that one employee was there, Lorimar Davidson, who spent four hours explaining both insurance and GEICO to Buffett. Buffett immediately grasped that GEICO would have an enduring competitive advantage. (Davidson subsequently became CEO of GEICO.) Insurance later became the primary business and building block of Berkshire Hathaway. "Warren Buffett has stressed the importance of luck in his life, focusing not only on where he was born but also when. His primary skill of allocation of capital has worked well for him in the United States and in his lifetime," Kass said. Michael Mauboussin, director of research at BlueMountain Capital Management and author of "The Success Equation," which looks at the role of skill and luck, said Buffett's example reveals something fundamental about business greatness: Positive outliers, including Buffett, "are the product of lots of skill and lots of luck ... in business dealings."

The one-in-seven billion slip that Buffett drew