Deal or No Deal relates to probability because it is more of a game of chance than a game of skill. You can bring a strategy to play the game but the only way to win is to pick random briefcases and hope that they aren’t the million-dollar briefcase. The best time to back out would be when you know that the million is out of play and the banker gives an offer that is as high as it gets before the offers start to decline. Some things that might influence the briefcase that somebody chooses might be what numbers they like, which ones are unlucky, how old they are, number of people in extended family, and so on. My strategy would be to try to get the million, but if the million is out of play, I would try to get the highest offer that the banker will give before they start to decline.