WIN ON DOUBLE DOZEN
You come to the roulette table and check the last 2-3 decisions.
You convert the numbers into dozens. If for instance you get 23, then you call it dozen 2. If you get 36 you call it Dozen 3 and so on. You bet one chip on two dozens that are different than the last one. If you lose, you press your bet by one extra chip on each dozen. If you lose, you press your bet by two extra chips on each dozen.
You need to win one more time than you would lose, because chances are more than 50% to win on two dozens.
When you win, you start with one chip again on each dozen.
If you get a zero, just bet on the two dozens that are different in the last few decisions.