The dealer shuffles a deck of cards, then begins to turn cards face up one-by-one. You can say “stop” at any moment, and if the next card is red – you win, and if it’s black – you lose.
It’s not difficult to prove that there is no winning strategy. No matter when you stop the process, you have an even chance.
In general, you cannot time the market http://en.wikipedia.org/wiki/Optional_stopping_theorem
In one of my next posts I’m going to tell about a much more exciting game, which is not a fair game though.
By the way, “martingale” is an anagram of “lame rating”