One of the best known and one of the oldest systems is the one with the black and red double the previous bet if the player loses. Assume that the player bets a brand to outside bets namely in red. If the number to be drawn is red, then the player wins when the system is over before it even starts with the player winning. In this case the system will restart from the beginning. However, if drawn black or zero, the player will have lost a brand so the next shot bet the red but this time again puts two chips. If he wins the red has won two brands but will have lost a chip from the first shot so it will be a total winner in one brand. So the system ends and the player repeats all over again.

In case you lose the second time, then the third shot will again bet the red but this time four brands. If he wins in the third round then you have won four brands minus 1 + 2 chips lost in the first and second shot, respectively. That will again won by a brand. If a player loses and then the third shot in the fourth round will bet 8 tokens. If winning is again one brand overall winner. If lost in the fourth round then the fifth will put 16 chips and so forth.

As is readily apparent, the player should have enough money to cover the size of the next bet if losing consecutively several times. If the player does not have enough money for the next bet and if the next bet has caught maximum allowable bet on the table, then the system will collapse. This is the risk of doubling system. For this to happen, the player should have lost several consecutive shots. -File recording and processing of previous results. Many players before they start playing, waiting patiently as they record the numbers that are drawn earlier shots. When you complete the required number of numbers needed, then process the data trying to find sequences of numbers, symmetries, lottery frequency of each number etc.