It took only one missed layup for most of America’s billion-dollar dream to end on Thursday.After the first game in the Quicken Loans Billion Dollar Bracket Challenge insured by billionaire Warren Buffett, four out of five would-be winners were already finished, thanks to Dayton’s upset of No. 6 seed Ohio State.By the end of first full day of the NCAA Tournament, two other major upsets whittled that number down to five percent of the registered players still eligible for the big prize.Out of the reported 15 million registrants, that leaves about 750,000 hopefuls remaining in the 1 in 9.2 quintillion chance for a billion dollar payoff Friday morning.That's higher than the national debt.After Dayton shattered the dreams of mansions and Lamborghinis for most participants, a couple of hours later No. 12 Harvard took down seventh-seeded Cincinnati 61-57.Those two upsets virtually eliminated the majority of everyone shooting for perfection even before most people had a chance to cry in their dinner.North Dakota State, No. 12 in the West, finished off the night by stunning fifth-seeded Oklahoma 80-75 in the third upset of the day.Bracketeers should not give up hope.People who get the top 20 scoring brackets will each win $100,000, though that money is reportedly being paid off either through payments on mortgages or a payment on a new house. Still, nothing to get upset about.