Nice liittle system like always ignatus.

(How many systems have you devised btw? do you keep them all in a notebook or something?)

Please let me make your examples a bit more specific and clear.

("doz" means dozen and "R/B" means Red or Black)

doz: 1, 1

R/B: B, B

Now we bet all BLACK numbers in doz 2 & 3.

That is: 13, 15, 17, 20, 22, 24, 26, 28, 29, 31, 33, 35

doz: 1,3,1

R/B: R, B

Now we bet all RED numbers in doz 1 & 2.

That is: 1, 3, 5, 7, 9, 12, 14, 16, 18, 19, 21, 23

doz: 2,3,1

R/B: B, B

Now we bet all BLACK numbers in doz 3 & 1.

That is: 2, 4, 6, 8, 10, 11, 26, 28, 29, 31, 33, 35