(re-post from here
Let's take a corner bet (4 numbers).
The corner bet has a 50% chance of appearing within 6 spins. We count from hit to hit. When it hits within 6 spins we record a A and if it goes beyond 6 spins without a hit we record a B.
A: Hit within 6 spins
B: Hit after 6 spins
M M H (A) M M M H (A) M M M M M M M M M M M M M M M H (B) M M M H (A) M M H (A) M M M M M M M M H (B) etc.
We then have a sequence of AABAAB... etc.
So what I do is count the spins between hits. Dividing the sequences in A or B, each of which has a 50% chance. We have created some sort of even chance and we record the results. These results are less extreme than your common Red Black High Low etc. results.
A further characteristic of this approach is that you can have even more information. For example you know that in average (long term) the H will be ~1/9 of total spins. Because we bet 4 out of 37 numbers, 37/4 = 9,25. All B sequences are not the same. A very long B sequence (MMMMMMMMMMMMMMH) can draw the average too much away from the 1/9 and (so to speak) increases slightly the probability of a correction.