I reckon doubling your profit and then also doubling the bet is not such a good idea.

Let's say you have a $300 bank and $30 liability (10% of bank). If you double your bank to $600 then I don't think you should keep laying at the same liability of 10% (in this case $60 liability).

I would slowly reduce the percentage of bank your laying with until you get to 2% or maybe 5%. In the above instance I would start laying to say 8% liability of the $600 making each bet $48 liability.

You are now raising your stakes but in a smaller proportion than your bank is increasing. As time goes on this would then give you more leeway by losing less of your bank should the method hit a bad trot.

Anyway, that's my 2 bobs worth (which is about all it is worth)

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Never give up on a dream just because of the time it will take to accomplish it. The time will pass anyway.”

― Earl Nightingale