[user104658]

There's only one sensible way to play the machines in my opinion. Two hands of blackjack, all in, then STOP. If you win both, you quadruple your money. If you lose, you walk out. Original stake as much as you're willing to lose.

So if you have a spare £5, you might walk out with 0 or a cheeky £20. If you are feeling a bit flush and want to risk £50, you leave with 0 or a nice £200. £50 is the most you can risk this way as your second hand is then a £100 stake which is max stake.