A few years ago, Jerry Selbee figured out how to legally win lotteries in Michigan. How? It was all about the roll down.
What is a roll down? In Michigan's WinFall lottery, if there was no grand prize winner that matched all six numbers from a field of 49 on a ticket and a jackpot limit was reached. Then instead of letting the jackpot grow, the lottery "rolled down" to give the next tier of players a chance to win. Instead of having to match all the numbers on a ticket, a winner would only need to match five, four or even three numbers to be a winner.