+EV betting glossary

Plain-English definitions of the terms you will run into on The Punt Edge and around the +EV betting world. Skim the list, or use your browser's search (Cmd+F / Ctrl+F) to jump to a term.

If you want the maths behind why +EV works, read how +EV betting works.

Arbitrage

Also called an arb or a sure bet. When two or more bookmakers price the same market differently enough that you can back every outcome across those books and lock in a guaranteed profit no matter which one wins. The edge is usually small (0.5 to 3 percent) and requires accounts at multiple bookies plus fast execution before the prices move. Arbitrage is separate from +EV, but the tools overlap.

Bankroll

The pool of money set aside specifically for betting. Ring-fence it from rent, groceries, savings, everything. Bankroll discipline is what separates recreational punting from anything serious. A common starting point is a bankroll you can afford to lose entirely without changing your life.

Closing line value

Closing line value (CLV) is the difference between the odds you took and the odds available at market close. If you took 2.00 on a team and the closing price was 1.85, you beat the market by 0.15. Consistently beating the closing line across many bets is the sharpest single measure of a winning bettor because it tells you the market moved in your direction after you bet. Long-term CLV strongly predicts long-term profit.

De-vig

Also called no-vig. The process of stripping the bookmaker margin (vig) from a price to reveal the underlying true probability. See how it works for the four-step arithmetic. De-vigging Pinnacle's price gives you the closest publicly available proxy for fair odds on a market.

Dutching

Backing multiple selections in the same market at stakes calibrated so you make the same profit no matter which one wins. Used when you can identify two or three plausible outcomes but do not want to pick one. Different from arbitrage (which covers all outcomes) and different from hedging (which is placed after the fact).

Expected value

Expected value (EV) is the average return of a bet if it were repeated infinitely. Positive expected value (+EV) means the average return is greater than the stake, so the bet is profitable in the long run. Formula:

EV = (probability of winning x profit if win) - (probability of losing x stake)

Or expressed as a percentage of stake:

EV% = (bookmaker odds x true probability - 1) x 100

A +5% EV bet returns 5 dollars on average per 100 staked, if repeated many times. Any single bet still wins or loses.

Fair odds

The odds that exactly match true probability with no bookmaker margin added. Calculated as 1 divided by true probability. Fair odds are theoretical, no bookmaker offers them (they would make no money). Comparing a bookmaker's offered odds to fair odds is what produces the EV percent.

Hedging

Placing a bet on the opposite side of a market to lock in profit or reduce loss on an original bet. Common in tournament or futures betting where a long-shot pick appreciates and you want to guarantee some return. Hedging costs you expected value in exchange for reduced variance.

Implied probability

The probability of an outcome as suggested by decimal odds. Equal to 1 divided by the odds.

implied probability = 1 / decimal odds

Odds of 2.00 imply a 50% probability. Odds of 1.50 imply a 66.67% probability. Odds of 4.00 imply a 25% probability. The implied probabilities of all outcomes in a market sum to more than 100 percent because of the vig.

Juice

Another word for vig. The bookmaker margin baked into odds. Used interchangeably.

Kelly Criterion

A stake-sizing formula that maximises long-term bankroll growth given the edge on a bet and the odds on offer. Full Kelly stake:

stake fraction = (probability of winning x (odds - 1) - probability of losing) / (odds - 1)

Full Kelly is aggressive and painful in variance terms. Most serious bettors use fractional Kelly (typically half-Kelly or quarter-Kelly) to reduce swings.

Line movement

A change in the odds or handicap on a market between opening and close. Movement is caused by new information (team news, weather, injuries) or by sharp money hitting the line and forcing the book to adjust. Reading line movement is a whole discipline on its own.

Overround

The sum of implied probabilities across all outcomes of a market. In a fair market the sum equals exactly 100 percent. Anything above 100 percent is the bookmaker margin. A market with an overround of 105 percent has a 5 percent vig. Lower overround = sharper market.

Pinnacle

A global sharp-focused sportsbook that operates on low margins (typically 2 to 3 percent on major markets), welcomes winning bettors, and does not limit accounts based on results. Because of these business decisions, sharp money flows through Pinnacle quickly and their prices tend to correct fast when the market misprices something. This is why Pinnacle's odds are widely used (including by The Punt Edge) as the reference for true probability.

Pinnacle is not available to bet with in Australia.

Player props

Bets on individual player performance rather than the overall match result. Examples: Nathan Cleary to score 20 or more points, Marcus Bontempelli 25 or more disposals, Josh Allen over 275.5 passing yards. Player props are where a lot of +EV opportunities live because bookmakers price them less carefully than game markets, and correlations between selections are hard to model.

Push

When a bet lands exactly on the line and the stake is refunded, no win, no loss. Common on spreads at whole-number handicaps and on totals at whole numbers. Bookmakers usually price these lines with half-points (like -5.5 or 47.5) specifically to eliminate pushes.

Same-game multi

A same-game multi (SGM) is a multi built from selections within a single event, for example "Melbourne to win + Petracca 25+ disposals + total goals over 22.5". SGMs are the dominant retail product in Australia because bookies push them heavily. They are also frequently mispriced because modelling the correlation between legs (a big win typically means high total goals, for example) is genuinely difficult.

Sharp money

Bets placed by consistently winning players (sharps or wiseguys). Sharp money moves lines because bookmakers respect the information value of a bet from a proven winner. When you see a sudden one-way move on a line without matching public news, that is usually sharp money.

Spread

A points handicap applied to a favourite or underdog to make the market a coin-flip proposition. Also called handicap or line betting. A spread of -6.5 on the favourite means they need to win by 7 or more for the bet to land. A spread of +6.5 on the underdog means they can lose by up to 6 (or win outright) and the bet still lands. Spreads are typically priced around 1.91 both ways.

Stake

The amount of money placed on a bet. Different from potential payout (stake times odds) and different from profit (payout minus stake).

Steam

A rapid, one-directional move on a line, usually caused by a burst of sharp money hitting the same side across multiple books. Chasing steam is not a strategy by itself but is a strong signal that the current line is soft.

Sure bet

Another name for arbitrage. A combination of bets that guarantees a small profit no matter the result.

Totals

A bet on whether the combined score of both teams (or both innings, both halves, etc) will be over or under a bookmaker-set number. Also called over/under. Totals are the second-most common market after head-to-head across most sports.

True probability

The best available estimate of an outcome's real chance of happening, once the bookmaker margin has been stripped from a market. Not truly knowable (no one has the actual probability distribution of a football match) but Pinnacle's de-vigged odds get close. True probability is the number we compare to bookmaker odds to calculate expected value.

Value bet

A bet where the offered odds are higher than the true probability of the outcome. Same idea as +EV. If true probability is 50 percent (fair odds 2.00) and a bookie offers 2.15, that is a value bet with a 7.5 percent edge.

Variance

The natural short-term swings in results around expected value. Positive EV bets still lose in the short run because of variance. A bet with a 55 percent win probability still loses 45 out of every 100 attempts on average, and in any given block of 20 you might win 8 or 14. Variance is why bankroll management and stake sizing matter as much as picking +EV bets in the first place.

Vig

Also called vigorish, juice, or the overround. The bookmaker margin built into odds so the book makes money regardless of outcome. A market with two-way odds of 1.91 / 1.91 has a vig of about 4.7 percent. The lower the vig, the sharper the market. Pinnacle famously runs 2 to 3 percent vig on major markets, whereas Australian bookies typically run 5 to 8 percent (and much more on props and SGMs).