Accumulator

A bet that is considered a sure winner, though no bet is ever truly guaranteed. The term is commonly used by tipsters and recreational bettors to express high confidence. Sharp bettors are skeptical of 'locks' because they understand that uncertainty is inherent in all sports outcomes.

A slang term for the favorite in a betting market. 'Playing the chalk' means betting on favorites. The term originated from the days when odds were written in chalk on blackboards. Heavy chalk refers to a strong favorite with very low odds.

A numerical representation of the likelihood of an outcome and the potential return on a bet. Odds can be displayed in decimal (2.50), fractional (3/2), or American (+150) format. Higher odds indicate a less likely outcome but a larger potential payout.

A virtual advantage or disadvantage applied to a team or player to level the playing field in a sporting event. For example, a -1.5 goal handicap means the team must win by 2 or more goals for the bet to win. Handicaps are used to create more balanced betting markets.

The maximum amount a bookmaker or a lay bettor stands to lose on a single bet. For bookmakers, liability is managed across thousands of bets. On a betting exchange, when you lay a bet, your liability is the amount you must pay the backer if they win. Understanding liability is essential for exchange betting.

The commission or fee built into the odds by the bookmaker. Also known as vigorish (vig), it represents the bookmaker's profit margin. For example, if both sides of a coin flip are priced at 1.91 instead of 2.00, the difference is the juice. Lower juice means better value for bettors.