Definitions of casino and gambling terms
The Kelly Criterion is a mathematical formula for determining the optimal fraction of your bankroll to bet based on your estimated edge and the bet’s odds. It maximizes the long-run growth rate of your bankroll without risking ruin. The Kelly formula Kelly percentage = (bp – q) / b, where b is the decimal odds…
An over/under bet (also called a totals bet) is a wager on whether a specified statistical total will be higher or lower than a number set by the bookmaker. In sports betting, the most common total is the combined score of both teams in a match. How over/under betting works The bookmaker sets a total…
A non-sticky bonus (also called a cashable bonus) is a bonus where the bonus funds can be withdrawn after wagering requirements are met — unlike a sticky bonus where only winnings are withdrawable. Non-sticky bonuses generally offer better value for the player. Example of a non-sticky bonus Receive a £100 non-sticky bonus. Wager it through…
Rollover is another term for wagering requirement — the number of times you must wager a bonus (or bonus plus deposit) before any associated winnings become withdrawable. A 30x rollover on £100 means you need to place £3,000 in total bets. Rollover calculations Most casinos calculate rollover on the bonus amount only. Some calculate it…
A sharp bettor (or simply ‘a sharp’) is a sophisticated, professional-level sports bettor who consistently bets with a mathematical or informational edge. Sharps are respected by bookmakers as accurate predictors of outcomes and their bets are monitored closely. How sharps differ from recreational bettors Recreational bettors (‘squares’) bet based on fandom, gut feeling, or widely…
A unit is a standardized measure of bet size used in sports betting to make comparisons between bettors meaningful. Instead of talking about dollar amounts (which vary by bankroll), bettors discuss performance in units — a 1-unit bet is a base stake that represents the same relative risk regardless of actual bankroll size. How units…
A moneyline bet is a straightforward wager on which team or player will win a contest outright. There’s no spread or handicap involved — you simply pick the winner. Moneyline betting is the most common format in US sports betting. Reading moneyline odds In American format, a negative moneyline (e.g., -150) shows how much you…
A spread bet is a wager on whether an outcome will be above or below a value set by the bookmaker, rather than a simple win/lose bet. Your profit or loss scales with how far the actual result falls from the spread — more extreme outcomes produce larger wins or losses. Financial spread betting In…
A wager is a bet — an amount of money risked on an uncertain outcome in the hope of winning more. To wager is to place that bet. The terms wager, bet, and stake are often used interchangeably in gambling contexts. Wagering in bonus terms The word ‘wager’ appears most often in casino bonus terms…
The grind refers to the slow, systematic process of meeting bonus wagering requirements through consistent low-variance play. Players who ‘grind’ bonuses aim to complete wagering requirements as efficiently as possible, minimizing expected losses along the way. Bonus grinding strategy The most efficient way to grind a bonus is to play high-RTP (96%+) low-volatility slots that…
A buy-in is the amount of money you exchange for chips at a casino table game. Sit down at a blackjack table, put down £100, and you ‘buy in’ for £100 worth of chips. In poker, the buy-in is the amount you pay to enter a cash game or tournament. Table buy-in minimums Most casino…
A near-miss in slots is an outcome where the symbols appear very close to a winning combination but don’t complete it — for example, two jackpot symbols on the payline with the third just above or below. Near-misses feel like ‘almost wins’ and are known to encourage continued play. Are near-misses random? In a properly…