This system is a combination of two of my systems "Dominant Dozen" and "Dozen Repeater", so it has been tested alot, and I KNOW it works, therefore i use no progression with this one, only flatbet.
TRIGGER: Wait for a dozen to repeat. -Bet all numbers in that dozen except the (one) or two numbers that repeated for 3 spins, then STOP. (10-11 numbers bet).