Had some luck with this one. it's 2-4 numbers bet. Key to this system is having a reasonable wingoal & stoploss -to know when to quit, because after X number of spins, chart will go down.
Procedure: A new doublestreet hit-- bet the 2 unhit numbers within the street hit, now start to calculate the cycle for 2 numbers 1-18 spins, IF no hit within the 18 spin cycle for 2 numbers. STOP & RESTART. IF the same unbet number hits within the street bet- double bets (for each time it hits), and reset calculation for the cycle of 2 numbers; 1-18 spins. IF the second street hit within the DS bet, also bet that one (at the two unhit numbers within that street hit) and double bets once. Now start calculate the cycle for 4 numbers 1-9 spins. IF any of the unbet number hits within the streets bet- double bets and reset calculation for the cycle of 4 numbers. (for each time it hits). IF no hit within the cycle for 4 numbers (9 spins). STOP & RESTART (reset progression to 1u and bet a new DS).
Bankroll needed: 200u minimum. Stoploss(?) you decide, but not higher than 100u (playing with 1u bets)
3 Games tested. (for demonstration purposes) played with 1u bets.