What is gamblers fallacy?

Gamblers fallacy occurs when an individual believes that the outcome of a casino game is determined by outside factors other than the game's odds. For example, if a roulette ball has landed on red 5 times in a row, a gambler may bet on black believing that as red has been the outcome so many times black has a higher probability of occurring. When in truth, the odds are always the same on every spin no matter what has occurred before.