This one has not been tested enough, and the martingale progression may be a bit risky, any other progression can be used perhaps? ideas are welcome.
Trigger: Wait until column 1 or 3 hits, if it was high or low same high or low is bet with 3 quads (on the two unhit columns in that particular high or low) and 3u on the opposite high or low.
For an example number 6 hits, that is LOW column 3.
Now 3 quads are placed at LOW, column 1 & 2; 1/5, 7/11 and 13/17.
3u is also bet on high.
Progression: double bets for each loss & keep the same bets for the next trigger until reach a new high (2 hits).