Billionaire CEO Warren Buffett has an NCAA men's basketball bracket challenge that just may blow other office pools out of the water.Buffett told CNBC last month that any Berkshire Hathaway employee who accurately predicts all Sweet 16 teams will receive $1 million per year for the rest of his or her life.The Oracle of Omaha went on to say that "if either Creighton or Nebraska ends up winning the tournament, we're going to double the prize."Buffett, a Nebraska native, is also offering a $100,000 prize to the employee whose bracket stays intact the longest.Last year, a steel worker from West Virginia correctly predicted 31 of the first 32 games and picked up his six-figure reward.Berkshire Hathaway owns more than 90 companies, including Geico and Dairy Queen.Here is a dose of reality that will calm your but-I-don't-work-for-Berkshire- Hathaway-itis:USA Todayreports the odds of accurately predicting the Sweet 16 are less than one in a million.Previously, Buffett offered $1 billion for anyone who predicted a perfect bracket.That feat has never been achieved in the 21-years that ESPN has been doing a bracket challenge.The odds of predicting a perfect bracket, according to USA Today, are anywhere from one in nine quintillion to about one in two billion. Copyright 2018 NPR. To see more, visit http://www.npr.org/.