This system isn’t as easy to master as others. Most commonly used on even-money bets like black or red, even or odd, 1-18 and 19-36, this system is also known as the Cancellation split or Martingale.
One choses a starting bankroll, and bets on a written sequence of numbers, making wagers on the first and last numbers of the list the player makes.
Starting with a 1-2-3-4-5-6 roll, the first bet is 7 chips (1+6). If the bet wins, on the list, one would cross out 1 and 6, continuing with 7 units (2+5). If it is a losing bet, one should add a 7 to the sequence, now having 2-3-4-5-6-7 – now the bet would be 9 units (2 + 7).
Starting with $100 in total, one would bet $7 each time, until the list is crossed out; a larger bankroll naturally increasing chances. The science is, because each time one crosses out two numbers, if the bet is a winning one, and adds one number with a losing bet, one only needs to win 33.3 per cent of the bets. Obviously, if the bankroll is lost, the system fails.
There is no guarantee a system will always win. However, the Labrouche offers incremental small wins to compensate a greater loss.