===================IF YOU HAVE LOST MONEY======================================

If you have put more money in to the bookies, than your balance shown at the bookies,
For instance, you put 31 pounds into the bookies
Plus a _small_ amount to 31
Eg 31 + 10 = 41
Call this moneyInPlusSome
Take away your displayed balance (accounting for any liabilities)
Times this by 1/ some kind of ridiculous top heavy odds

amountToBet = (moneyInPlusSome - displayedBalance) * 1/(topHeavyOdds)

As an example;
If your balance said £10 at the bookies,
and you had put £41 from your bank account in,
and there is a 1000/1 odds that pigs will fly to to your house tomorrow,
the equation would become:

amount to bet = (41 - 10) * 1/(1000/1)

So you would bet £0.031, rounded upwards to 4p

You only get so many chances to earn your money back, if you do not succeed, give up and do not give any more money to the bookies.

As soon as you get your money back plus some. Withdraw the total amount of money you have handed to the bookies, in the example above, leaving £10.

=====================IF YOU HAVE GAINED MONEY==================================

If you have a balance of £20, and you have all the money back that you have put in, you should aim to double your balance.

in this instance moneyPlusSome would be £40

So using the pigs flying odds:

amountToBet= (40 - 20) * 1/(1000/1)

in which case you would bet 2p.