A **betting strategy** (also known as **betting system**) is a structured approach to gambling, in the attempt to produce a profit. To be successful, the system must change the house edge into a player advantage — which is impossible for pure games of probability with fixed odds, akin to a perpetual motion machine.^{[1]} Betting systems are often predicated on statistical analysis.

Mathematically, no betting system can alter long-term expected results in a game with random, independent trials, although they can make for higher odds of short-term winning at the cost of increased risk, and are an enjoyable gambling experience for some people. Strategies which take into account the changing odds that exist in some games (e.g. card counting and handicapping), can alter long-term results.^{[1]}^{[2]}^{[3]}

This is formally stated by game theorist Richard Arnold Epstein in *The Theory of Gambling and Statistical Logic* as:

Theorem 1:If a gambler risks a finite capital over many plays in a game with constant single-trial probability of winning, losing, and tying, then any and all betting systems lead ultimately to the same value of mathematical expectation of gain per unit amount wagered.^{[1]}

Common betting systems include:

- Card games – Card counting
- Roulette – Martingale
- Sports – Handicapping
- Martingale
- Kelly criterion
- Split martingale
- Anti-martingale
- d'Alembert system
- Oscar's grind

Some Horse racing betting systems can be based on pure statistical analysis of the odds, while others also analysis of physical factors (e.g. the horses' form, jockey form and lane draw). Common forms of betting systems for horse racing are:

- hedging- betting on multiple outcomes in a race
- arbitrage- lay the horse a low price and back it at a high price.

**Sports Betting (Modelling)**

Modelling in sports betting requires the development of predictive mathematical algorithms to process data usually in large amounts in order to come up with an estimate of what the true odds of an event are.

Modellers will use their model's outputs to place value bets when the odds being offered by a bookmaker or an exchange have higher payouts than their model's prediction's imply they should.

Modelling in very hard and requires a strong foundation in maths and data science.

**Sports Betting (Cloning)**

Cloning involves using odds that already exist to base your estimates of true odds.

Cloner's will use odds generated by sharp bookmakers like Pinnacle and exchanges like Betfair Exchange to come up with their estimates of true odds as they are 'sharp' operators who have the most accurate odds in the world.

**Dropping odds strategy:**

Since 2017 cloners started using a new strategy that has since become a popular of beating bookmakers. The dropping odds strategy involves waiting for Pinnacle to drop their odds at which point placing a bet at another bookmaker like Bet365 who haven't yet dropped their own odds meaning they are still offering the old more generous odds that pay out more.^{[4]}

Most bookmakers simply copy Pinnacle when it comes to pricing their odds but on a 20 second to three minute delay which is why the opportunity for placing a value bet exists.

Dropping odds alert services like Pinnacle Odds Dropper have spawned in the last few years to alert bettors to drops in any of Pinnacle's thousands of markets so that bettors can find value at other softer bookmakers.