... probabilities, since red & black will, over time, be equally distributed. A British Duke named Martingale developed a "system" for roulette, based on those probabilities. It was quite popular in 18th Century France. He would double each bet until he won. In order to be foolproof, the system requires an unlimited bankrole. He died broke. There are those who try the same thing in Blackjack. They also will eventually lose. I have seen streaks of 10 hands going to the dealer. Starting at $10, the last hand would require a bet of $5120 just to net $10.