Nine Shooter

[ignatus]

imagine the carpet diveded into four parts, each nine numbers: 1-9, 10-18, 19-27, 28-36.

Now, wait until one part has not been hit for 9 spins.

then start betting that one with a nine numbers negative progression:

1,1,1,2,2,3,4,5,7,9,13,17

[nottophammer]

have you looked into this any more.
how about four spins and two groups of four missing back the missing two?