It is old simple system which covers almost whole table.
Trigger to play is repeat of double street 2 or better 3 times. Then you left out that double street.
Second variant is to first mark 18 spins and bet against the weakest performing street.
Streets sometimes sleep for 30 spins.
Bet 3 units on L/H; 1 unit on double street: 1 unit on double street.
Sometimes you bet 3 units on L/H and 2 units on corresponding dozen. After loss double all bets.
Example of double streets play: 6-2-3-4-1-1-1 (trigger is 1) bet H 3 units, 13/18 1 unit; 7/12 1 unit and if lose H 6units; 13/18 2 units; 7/12 2 units.
Didn't I told you it is easy?
Cheers Hermes
No questions yet? Must be really simple!
The second version could be played so that you wait until the slowest double street shows up and then bet the progression if needed. Mostly it comes as a single. Best to play on French roulette where you get your money back on H/L if repeat or that one which pays 50% automatically back after zero.
Cheers Hermes