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.
Unless you use software which would tell you which parts of the wheel are coming up now.
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.