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Jargon Busting

Updated: Mar 28, 2021

Welcome to another article in the Introduction to Betting series, where we bust some betting jargon terms that you might hear along the way. If you're new to betting, or even if you’re not, there may be a lot of terms that are unfamiliar to you. Here is a glossary containing definitions of some key betting terms you may come across.

Arbitrage (arbing): This is a betting technique used to lock in profit despite the outcome. It works by taking advantage of a situation where odds on bookmaker site are higher than the lay odds on an exchange. This is a type of matched betting, and is explained in more detail here.

Bet slip: The bet slip is the website pop-up (for an online bookmaker), or the piece of paper (for a shop bookmaker) where the details of the bet to be placed are recorded and submitted.

Cash-out: Cash-out is a feature offered by many bookmakers whereby you can instantly receive a guaranteed return from a bet that you placed. The return is dependent on your original stake and how much the bookmaker odds have changed. We explain cash-out on more detail here.

Each-Way: An each-way bet is a type for bet where you are simultaneously placing two bets - one on the selection to win and the other on the selection to place. The two bets have identical stake, and the odds of your place bet are determined from the odds of the win bet by use of the ‘each-way’ fraction. We explain each-way betting in more detail here.

(Betting) Exchange: A betting exchange can be used similarly to a bookmaker by betting on an outcome at set odds, however the odds are not set by the website. An exchange acts as a platform for users to bet for or against each outcome while continuously matching off opposing bets against each other. This system determines the odds available at any given time. Exchanges are also used for alternative betting techniques such as trading - more information on exchanges is available here.

Expected Value (EV): The ‘expected value’ of a bet is the average profit that you will receive from the bet in the long-run. The concept of expected value is discussed in more detail here.

Implied probability: The implied probability of a runner is the probability of the runner winning that is implied by the odds. For decimal odds it is simply:

implied probability = 1/odds

It is more specifically described as the probability of the runner winning that would be required to be for the the odds to represent 0 expected value.

In-Play (In-Running): In-play (or in-running) betting is the action of placing a bet when the event you are betting on is in progress.

Lay Betting (Laying): Lay betting is the act of betting against a particular outcome occurring. It is a common way of betting on betting exchanges.

Liquidity: On Exchange markets the liquidity refers to the amount of money that is available to bet, and the rate at which bets are being matched (the same concept as in financial markets and economics). There is no standard exact measure for this in betting markets, as it is only useful as a rough relative judgement of high/medium/low.

Margin: Your margin in betting is a measure of the profitability of your bets and is calculated using the following formula:

margin = profit/stake = (returns/stake)-1

You can also consider 'expected margin' by replacing 'profit' and 'returns' with 'expected profit' and 'expected returns' from the expected value formula.

Market: A betting market comprises the runners and odds available for a given event.

Matched Betting: This is a betting technique used to lock in profit no matter the outcome, by taking advantage of bookmaker promotions and/or situations where odds on bookmaker site are higher than the lay odds on an exchange ('arbitrage'). Matched betting is explained in more detail here.

Odds: The odds of a bet determines how much you will get paid if you win the bet. Odds will either be displayed in ‘decimal’ or ‘fractional’ form - explained in more detail here.

Over-round: The over-round of a market is a measure of how generous the odds are in the market as a whole. It is calculated by summing the inverse of the odds of each of the runners (R = number of runners). We explain over-rounds in more detail here.

Runner(s): The runners are the possible competitors available to bet on in a particular market.

Selection(s): A selection is the particular runner that has been chosen for a bet.

Stake: The stake of a bet is the amount of money that has been bet (or ‘wagered’) on the outcome. For a normal back bet this is the maximum that the bettor can lose from the bet.

True Odds: The true odds of a runner, are the odds that accurately reflect the probability of the runner winning. If you place a bet at the true odds your expected value will be 0. For decimal odds it is simply:

true odds = 1/probability

Are there any betting terms that we have missed out? If so, please let us know.

Happy Betting!

Gamble responsibly: BeGambleAware

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