I had a similar idea but with 2 dozens or 2 columns, there is 1 bet per 3 spins (disregarding results on 0), if the first 2 spins of the 3 spins cycle are 2 different dozens or columns then we bet those 2 once, if the same dozen or column repeat on last 2 spins then we bet the other 2 dozens or columns on the 3rd, final spin of the cycle.