On a roulette wheel, you might try the ‘Sleepers’ system taken from Alex Passe’s Roulette Systems. Record each number for 108 spins. Check which numbers have not come up at all, then bet progressively on those numbers until they win. On most times, there will be between two and five sleepers after 108 spins, and once the betting begins, a single chip is bet on each.
If the sleeper does not come up during the first 34 bets, the bet is increased to two chips for 17 spins, three for the next 12, four for the next nine and five for the next seven. There are very few sleepers which do not come up in 187 spins. Bets are placed on each spin of the wheel, on the column and dozen which came up on the last spin. In the case of a loss, the stake is increased by one unit for the following spin.
In the case of a win, the stake remains the same. A starting capital of 12 chips will enable a third bet to be made on both a column and one of the dozens even if the first two bets are lost. Play should be stopped when these 12 chips have been doubled.