You’re using the technique to change your high chance of losing a small amount into a small chance of losing a high amount.

The less likely you make the loss, the more catastrophic it is if it happens.

You can achieve the same thing by backing very low odds, laying high odds, on an exchange – you’re unlikely to lose on any given bet, but guess what happens if you run the maths for the long term…

The only way to beat this is if you’re backing at higher than true odds, or laying at lower than true odds. But if you’re managing to do that, there’s no need for all the fancy doubling-up and such systems.