Hi. Im posting this for You to evaluate. A discussion around it may arise. Since im breaking my own rule by not have tested this for 3000 spins. Therefore its Ok to debate it in an objective way.
The movement of the Columns is:
COL: 1->2->3->1
The movement of the Dozens is:
DOZ: 1-2, 1-3 , 2-1, 2-3, 3-2, 3-1
So when we see These Last Dozens:
DOZ: 1-2 = LOW
DOZ: 2-1 = LOW
DOZ: 1-3 = LOW
DOZ: 3-1 = HIGH
DOZ: 2-3 = HIGH
DOZ: 3-2 = HIGH
Play H/L and the Columns and stop at +3 units at least.
Cheers!