Page "Law of averages" Paragraph 2

* Belief that an event is " due " to happen: For example, " The roulette wheel has landed on red in three consecutive spins.

The law of averages says it's due to land on black!

" Of course, the wheel has no memory and its probabilities do not change according to past results.

So even if the wheel has landed on red in ten consecutive spins the probability that the next spin will be black is still 48. 6 % ( assuming a fair European wheel with only one green zero: it would be exactly 50 % if there were no green zero and the wheel were fair, and 47. 4 % for a fair American wheel with one green " 0 " and one green " 00 ").

( In fact, if the wheel has landed on red in ten consecutive spins, that is strong evidence that the wheel is not fair-that it is biased toward red.

Thus, the wise course on the eleventh spin would be to bet on red, not on black: exactly the opposite of the layman's analysis.

) Similarly, there is no statistical basis for the belief that a losing sports team is due to win a game or that lottery numbers which haven't appeared recently are due to appear soon.

This sort of belief is called the gambler's fallacy.