Take a look at this
https://www.olbg.com/forum/viewtopic.php?f=31&t=23538
It's a guy using a variant of the martingale system. Say you start off with £100 and place a £3 bet (you always bet at around 2 in odds). If you win, you're up to £103. If you lose, you're down to £97, but you then bet £6 to make up for what you just lost. If that fails, you then bet £12. Then £24. Then 48. If you lose at 48 you're pretty much out of money,
but you're absolutely rubbish if you lose 5 bets in a row with an odds of 2. If that feels too risky for you you could lower the risk by doing 2/4/8/16 etc or starting with 200 and not 100, or playing on different odds. Either way it should work. It doesn't work in casinos because the odds of winning in roulette is somewhere around 46%. In football betting however, it should work right? I think I'm going to do this with £100 and try to get it up to £200 before pulling out. Thoughts?