Core terms
Odds (decimal)
Total payout per 1 unit staked. 2.00 = double your stake.
Implied probability
1 ÷ decimal odds. 2.00 implies 50%.
Margin / overround
The combined book percentage above 100%. Lower is better for the bettor.
Vig (juice)
The bookmaker's margin built into the odds.
Stake
The amount you wager on a single bet.
Market types
1X2 / Match result
Home win, draw or away win.
Asian handicap
Removes the draw by giving one side a virtual head start expressed in half-goals or quarter-goals.
Over/under (totals)
Bet on combined goals/points being above or below a line.
BTTS
Both teams to score — yes or no.
Same-game multi
Multiple correlated selections from one event combined into a single price.
Strategy terms
Closing line value (CLV)
Difference between your taken price and the market closing price.
Expected value (EV)
The mathematical average profit/loss of a bet over many trials.
Kelly criterion
A staking formula that maximises long-run bankroll growth.
Sharp / square
Sharp = professional/winning bettor. Square = recreational/losing bettor.
Live Polymarket markets
Real-time prices and 24h volume from Polymarket.
Most losing bettors lose because they do not understand what they are buying. The glossary above fixes that.
How to use this page
Bookmark it. Refer back any time you encounter a term you are unsure of.
Next step
Once the vocabulary is familiar, move on to our getting better at betting guide.