Gambling is largely predicated on the randomness of results. But can betting systems be used to guarantee, or improve the chances of, a profit?
The Appeal of Betting Systems
Whether it's finding order in the chaos of randomized results or honing a perfect strategy to guarantee long term profits, the ideal of a systemic approach to gambling has been around for a long time. But there's a problem. By definition, casinos have to finish ahead (or they'd go out of business) so can these strategies actually work?
The Martingale Betting System
The Martingale strategy involves increasing stakes to cover previous losses and end up ahead overall when betting on a 50/50 type bet. To put it in context, this might mean an initial stake of $1. And if you win, that's great, it's $1 green. But if you lose, the next stake rises to $2. If that loses, the stake goes to $4, and so on, the basic idea is that if you win any one of those bets, you're ahead by $1 overall. If the initial bet wins, then the next stake stays at $1, with increases only occurring following a lost bet.
There is some attraction to this strategy. For a roughly 50/50 bet, you're unlikely to lose many in a row. But unlikely things can and do happen. If you were to lose a dozen bets consecutively, then even with the $1 starting stake, you'd be wagering thousands of dollars on the last bet. And if you're starting with a $1 bet then it's unlikely a thousand dollar loss is something you want to suffer. And that's before we get to table limits on stake sizes.
The major problem with this approach, though, is that it will usually make you a winner. But if you're very unlucky, it'll cost you a huge amount. And the more you play, the greater the chances of that unlucky streak coming about.
The D'Alembert Betting System
Initially similar to the strategy above, the D'Alembert system begins with a nominal stake (let's say $1). If that bet loses, the stake rises to $2, and then to $3 (NB not $4 as it would with Martingale). When a bet comes off, the subsequent stake declines by $1 instead. If the initial bet wins, the stake stays at $1.
Because the stake varies by addition rather than multiplication, this avoids a $1 stake turning into thousands of dollars wagered after a dozen lost rounds of betting. However, it also ends up chasing losses by increasing stakes. Whilst this strategy leads to a higher chance of finishing ahead in the short term, in the long term it will go wrong and that will mean a large loss (albeit smaller than with the first method).
The fundamental problem with applying a mathematical betting system to casino gambling is simply this: the casino always has the mathematical advantage. The best piece of advice is to follow the golden rule of betting: only bet what you can afford to lose.