Many people have formulated staking systems in an attempt to “beat the bookie”, but most still accept that no staking system can make an unprofitable system profitable over time. Widely-used systems include:

• Fixed stakes – a traditional system of staking the same amount on each selection. This method suits conservative punters if the stake remains below 5% of the bank.
• Fixed profits – the stakes vary based on the odds to ensure the same profit from each winning selection. This method suits conservative punters well, although if the profitability of one’s bets varies independently of the odds the bettor simply reduces his or her cash flow.
• Due-column betting – A variation on fixed profits betting in which the bettor sets a target profit and then calculates a bet size that will make this profit, adding any losses to the target. For example, to make a target of $100 profit a bettor would wager $50 at odds of 2 to 1. If the bet loses, the target becomes $150. If the next bet is also at odds of 2 to 1, the wager therefore becomes $75. This type of wagering can prove ruinous in the long run.
• Kelly (optimal) – the punter needs to estimate fair odds (in the European/decimal format) and then calculate the stake using :

Stake= (Odds/(Fair odds-1))/(Odds-1) Many times used with a divider (most commonly 4 or depending on your bankroll (for betting)

• Martingale – A system based on staking enough each time to recover losses from previous bet(s) until one wins. It is usually applied to even-money bets such as red/black on roulette. The Martingale guarantees failure in the long run – it would only work if the bettor has an unlimited bankroll, the bookmaker has no limit on the size of bets and neither party ever dies. However, it can usually be used to gain a small win in the short run, given a bankroll large enough to survive a streak of five or six losses.

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.