To play roulette, you need to know the classics. The Great Martingale is actually a variant of the Hawks martingale (or simple martingale).
The principle of the Great Martingale
the principle is simple, if the black just came out, you have to play on the red until the red will come out. Every sequence has necessarily an end and the longer the greater the chance of stopping. The red is bound to eventually emerge after a while. If you double your last bet every time you lose you will end up winning and necessarily erase your losses. On a sudden you get all your losses and earn the equivalent of your first bet. This is the Martingale Hawks.
The Great Martingale consistes of a double of the previous bet but to add it a unit.
Schema of bets with Hawks Martingale :
1, 2, 4, 8, 16, 32, 64, etc...
Schema of bets with the Great Martingale :
1, 3, 7, 15, 31, 63, 127, etc...
Example of game with Hawks martingale :
You have a winning wager after losing six:
So you bet : 1 then 2 , 4 , 8 , 16 , 32
Total of losings : 63
On the 7th bet, 64, you win: 64
You won 1 (64-63).
Example of game with Great martingale :
You have a winning wager after loosing 6 times :So you bet: 1 then 3 , 7 , 15 , 31 , 63
Total of losings : 120
On the bet 7th, you win : 127
You won 7 (127-120).
Limitations
The limitations of this martingale are the same than Hawks martingale which are a runaway of bets and the reaching to fast of the maximum bet.
Overcoming limitations
We could wait for a 4 color, 5 times to get to play but this would take time and enorment not change with a series of 15 consecutive Reds.
In conclusion
The Great Martingale works very well but on the short term. This martingale has the advantage of a reporting unit for move. We recommend that you use this method to target a gain of 30% to 40% of capital base. From 100 $ to 140 $ is a reasonable goal with this method but increased from 1000 $ to 1400 $ is much less.