15 bet

The pockets of the roulette wheel are numbered from 0 to 36. In number ranges from 1 to 10 and 19 to 28, odd numbers are red and even are black. In ranges from 11 to 18 and 29 to 36, odd numbers are black and even are red.

There are 18 black slots, 18 red slots and two green slots (0 and 00) on a US roulette wheel*. Your chances of hitting a black or red are equal, 47.4%. This translates to a 52.6% probability that the house will be scooping up all your chips on a black/red bet.