I have one thought on this betting strategy.
First you do not know where the ball is going to land for certain.
You need help.
(18 numbers, a 1/2 wheel bet) this makes it harder to work out where the ball will go or will not go, I think in the long run it would be to hard to predict.
There are 4 parts of the wheel 2 parts have 9 numbers.
2 parts share the Zero & have 10 numbers on a single Zero wheel.