Let me clarify:

Start the game with normal rules.

When you get to the point where you are placing six units on the table to cover the double streets that have come up; you also place one unit covering 0, 1, 2 and 3 as an insurance bet. Increase the chip by one unit every six spins.

If the first double street ( 1, 2, 3 , 4, 5 and 6) is in play and the numbers 1, 2 or 3 hits then you have an added bonus.