gambler’s fallacy
a failure to recognize the independence of chance events, leading to the mistaken belief that one can predict the outcome of a chance event on the basis of the outcomes of past chance events. For example, a person might think that the more often a tossed coin comes up heads, the more likely it is to come up tails in subsequent tosses, although each coin toss is independent of any other and the true probability of the outcome of any toss is still just .5.