Thanks Nickmsi for your explanation.

As I see it, if you bet a fixed color, example, RED only,

Then,

The 123 same as 234, 345, 456, 567, 678, 789,

Which are streaks of three in row.....rrr

The 135, same as 246, 357, 468, 579.

Which are chops, rbrbr...

The 147 same as 258 and 369...

Which are rbbrbbr....

And 159 the only rbbbrbbb

Thus lose if the pattern breaks. ...when we bet the "third"

Thus if 2persons bet opposite color, then a person must hit....in the 9spins.