Zero
British roulette wheels have '0', which is green rather than red/black, and losing bets on red/black or other even money bets lose half if zero comes in.
Bets on the dozens and columns (3:1) just lose if zero comes in. The trouble with chasing losses by doubling your stake is that when you lose, you lose massively, and when you win, most of it is immediately swallowed by the preceding losses.
Lots of punters who play large on these outside bets will also put a few quid on zero, just in case, furthering their losses.
It's been a few years since I was a croupier, but the fact that casinos are still profitable disproves every theoretical system ever.
The best system (without cheating or counting cards) is to play blackjack after memorising every correct decision (pretty easy, most of them are obvious) and even then, its still just fair, there's no advantage to either you or the house.
The casinos love, and actively encourage, the illusion of these systems, because if people actually realised that they had fucks chance, they'd stay at home, and as long as there are punters at the tables, the casinos will rake it in.
I'm no anti-gambling evangelical, I've had some great nights in Casinos, but you won't if you expect to win.

/bitter ex croup blog
(Udidin is chuffed to have made the newsletter, Tue 5 Aug 2008, 21:17, Reply)