Betting Glossary

Betting edge is the gap between what a bet should cost and what a sportsbook is charging for it. Dynatyze strips the vig from the sharpest consensus market to find a fair line, then compares it to the best price available — when the best price implies a lower win chance than the fair line, that difference is your edge.

Edge is probabilistic, not a promise. A 5% edge still loses plenty of individual bets; it only shows up over a few hundred plays.

A fair line is the price a bet would carry if the sportsbook took no commission — the true 50/50-relative odds with the vig removed. Every Dynatyze edge is measured against a fair line built from de-vigged consensus pricing.

A fair line is an estimate of true probability, not a decree. Books reprice constantly, so the fair line is a moving target, not a fixed number.

De-vigging is the act of removing the commission a sportsbook bakes into both sides of a market so the two implied probabilities add up to 100% instead of 105%. A -110/-110 market implies 52.4% on each side; de-vigged, each side is a true 50%.

De-vigging assumes both sides are equally sharp. When one side is all public money and the other is sharp, that assumption breaks and the no-vig line skews.

Expected value is the average profit or loss a bet would return if you placed it an infinite number of times. A positive-EV bet wins money long-term even when it loses tonight; a negative-EV bet bleeds money even when it cashes.

EV is calculated as (win probability × profit) minus (loss probability × stake). The whole game is finding prices where your win probability beats the price the book is offering.

Vigorish is the commission a sportsbook charges on every bet, built directly into the odds. A standard -110/-110 market carries about 4.76% vig — the book's guaranteed margin if action lands evenly on both sides.

Vig is rent you pay to play. Shopping for the lowest-vig price on a market is the single cheapest way to add expected value.

Implied probability is the win chance baked into a set of odds, expressed as a percentage. Odds of -110 imply a 52.4% chance, +200 implies 33.3%, and the conversion is the first step in spotting whether a price is fair.

The implied probabilities on both sides of a market always sum to more than 100% — that excess is the vig. Remove it and you get true probability.

The Kelly Criterion is a staking formula that sizes each bet as a percentage of your bankroll scaled to the size of your edge. A bigger edge earns a bigger stake; a thin edge earns a small one, so the bankroll grows at the fastest sustainable rate without going broke.

Full Kelly is mathematically optimal but brutally volatile. Most disciplined bettors run quarter- or half-Kelly to survive the variance and stay under book limits.

Closing-line value measures how smart you were the day you placed the bet, not how lucky you got. It compares the price you took to the final price the market settled at — beating the close consistently is the strongest evidence that a bettor has a real, repeatable edge.

CLV can be positive even on a losing bet and negative on a winner. It grades the decision, not the outcome — which is exactly why sharp bettors track it.

Sharp money is wagering placed by professional bettors whose bets move the line because books respect their track record. Sharps bet in lower volume but higher precision than the public, so a small sharp wager can move a market more than a flood of recreational tickets.

Sharps are not infallible — they hit roughly 53-57% of the time. The edge is in the price they take, not a magic crystal ball.

Steam is a rapid, simultaneous line move across multiple sportsbooks in the same direction. When a number jumps at every book within minutes, it signals coordinated sharp action rather than one book reacting to its own lopsided tickets.

Chasing steam after it lands usually means betting a worse number than the sharps got. The value was in front of the move, not behind it.

Reverse line movement is when a line moves opposite to where the betting tickets are piling up. If 75% of bets are on the favorite but the favorite's price gets cheaper, sharp money is hitting the unpopular side — the line is following the money, not the crowd.

RLM is a flag, not a guarantee. Confirm it against your own read before fading the public on it alone.

Tickets vs money is the split between how many bets a side has versus how many dollars are on it. When 70% of tickets sit on one side but only 40% of the money does, a few large sharp wagers are outweighing many small public ones — a classic sharp-versus-public tell.

The gap between the two percentages is the signal. A side with few tickets but most of the money is where the respected dollars are sitting.

Line movement is any change in a price or point spread between when a market opens and when it closes. Movement is driven by money coming in, news breaking, or books adjusting to balance their exposure.

Timing matters: morning moves usually carry sharp money, afternoon moves usually carry the public chasing, and the final 30 minutes belongs to sharps again.

Market consensus is the agreed-upon price on a bet once you blend the sharpest books together. Dynatyze builds its fair lines from consensus pricing because no single book's number is as reliable as the weight of the whole market.

Consensus weights the books that price most accurately. A regional book that lags the market should not move the consensus much.

American odds express a price as a number prefixed by a plus or minus. A minus number (-150) is how much you stake to win $100; a plus number (+150) is how much you win on a $100 stake — the format used by every major US sportsbook.

The closer the number sits to even (around -110 / +100), the closer the bet is to a coin flip after vig.

Decimal odds express the total return per $1 staked, including the stake itself. Odds of 2.50 return $2.50 on a $1 bet — $1.50 profit plus your dollar back — making them the cleanest format for calculating expected value.

Decimal odds convert to implied probability simply: 1 divided by the decimal price. 2.50 implies a 40% chance.

Fractional odds express profit as a fraction of the stake, the traditional UK and horse-racing format. Odds of 5/2 pay $5 profit for every $2 risked, plus the stake back.

Fractional odds are rare on US prop markets but still appear on futures and racing boards.

A point spread is a handicap the favorite must overcome to win the bet. A team listed at -6.5 must win by 7 or more to cover; the underdog at +6.5 covers by winning outright or losing by six or fewer.

The half-point hook (the .5) exists to remove ties so every spread bet has a clean winner and loser.

An over/under, or total, is a bet on whether a combined number will land above or below a posted line. It applies to game scoring, a player's stat line, or any countable outcome — bet the over if you expect more, the under if you expect less.

Totals are priced with vig on both sides just like spreads, so the over and under are rarely a clean 50/50.

A moneyline is a bet on which side wins outright, with no spread attached. The price reflects how lopsided the matchup is — a heavy favorite pays little, a long-shot underdog pays a lot.

On big favorites the moneyline carries steep juice, so the implied break-even win rate climbs fast.

Juice is the extra cost baked into a price beyond the true odds — the same thing as vigorish, expressed from the bettor's seat. When a side moves from -110 to -120 without the point changing, the book raised the juice, not the line.

A juice-only move (price worse, number unchanged) is a margin adjustment, not a sharp signal about the outcome.

A player prop is an over/under bet on a single athlete's individual stat line — passing yards, points, rebounds, strikeouts. Props price one player's role and matchup rather than the game result, which makes them the deepest pool for finding mispriced numbers.

Props move on news fast. An injury to a teammate can swing a player's projected workload before the book reprices the number.

A prop screener is a tool that filters hundreds of player prop markets at once by edge, line, matchup, and hit rate. It replaces eyeballing one game at a time with a sortable board that surfaces the mispriced numbers fastest.

Hit rate is the share of recent games in which a player landed on the over or under side of a given prop line. A player who has gone over 22.5 points in 8 of his last 10 games carries an 80% recent hit rate against that number.

Hit rate is descriptive, not predictive — it measures the past against tonight's line and must be weighed against matchup, role, and sample depth.

A parlay is a single bet that ties several outcomes together, all of which must win for the ticket to cash. The combined odds multiply, so a parlay pays far more than its legs separately — but one missed leg loses the whole stake.

Books love parlays because the vig compounds with every leg. A four-leg parlay of -110 legs hands the book a margin several times larger than a single bet.

A teaser is a parlay that lets you move the spread or total in your favor on each leg in exchange for a reduced payout. A 6-point football teaser shifts every leg six points your way, but all legs still must win together.

Teasers only beat the vig when the points cross key numbers like 3 and 7 in football. Off the key numbers, the reduced payout usually erases the benefit.

A same-game parlay combines multiple bets from one game onto a single ticket. Because the legs are correlated — a quarterback throwing for 300 yards makes his receiver's yardage prop more likely — books price SGPs with extra margin to cover that linkage.

The book's correlation adjustment is where most of the edge disappears. Treat the quoted SGP price as already padded against you.

Correlation is the degree to which two betting outcomes rise and fall together. Positive correlation — a high game total and a star receiver's yardage over — makes both more likely at once, which is exactly why books restrict or reprice correlated parlay legs.

Finding correlation the book has not priced is one of the few durable edges in same-game markets.

An alternate line is a version of a market set away from the standard number, with the price adjusted to match. Buying a passing-yards prop down from 250.5 to 200.5 raises your win chance but shrinks the payout; buying it up to 300.5 does the reverse.

Alt lines are how you express a strong opinion at a price — and occasionally where a book's pricing of the tails is softest.

Middling is betting both sides of a market at different numbers so a result landing in the gap wins both bets. Take the over 44.5 early and the under 47.5 after the line moves, and any total of 45, 46, or 47 cashes both tickets.

Even when the middle misses you usually lose only the vig on one side, which makes a well-priced middle a low-risk, high-upside play.

Arbitrage is betting every outcome of a market at different sportsbooks so the combined prices lock in a guaranteed profit no matter the result. It only exists when two books disagree enough that their no-vig prices leave a gap.

Arbs are real but fragile — typically 0.3-0.8% returns that vanish in under 90 seconds, and books that catch you arbing will limit or close the account.

A betting exchange lets bettors wager against each other instead of against a sportsbook, with the platform taking a commission on winnings. Because there is no built-in vig on the price, exchange odds are often the truest read on a market's fair value.

Exchanges let you lay a bet — take the book's side of an outcome — which opens hedging and trading strategies unavailable at a traditional book.

DFS pick'em is a daily-fantasy product where you choose more-or-less on a slate of player projections, paying out on how many picks land correctly. It looks like prop betting but is structured as a fantasy contest, with the platform setting the lines.

Pick'em lines often lag the sportsbook market, so a sharp sportsbook number can flag a soft pick'em projection.

DFS overlay is when a guaranteed-prize contest fails to fill its entry slots, leaving the operator to cover the shortfall. Overlay is a rare gift of positive expected value — the prize pool is larger than the entries paid in to support it.

Overlay favors entering large guaranteed contests late, once it's clear the field is short, rather than small or capped ones.

Bankroll management is the discipline of sizing every bet relative to the total money you have set aside to wager. Proper sizing keeps a normal losing streak from wiping you out and is the difference between a bettor who survives variance and one who busts.

Even a genuine long-term edge will go broke if it bets too large into a routine downswing. Sizing is risk control, not timidity.

A unit is a standardized bet size expressed as a fixed share of your bankroll, usually 1%. Tracking results in units instead of dollars lets you compare performance honestly across bankrolls of any size.

A pick reported as +3.2 units means it returned a profit equal to 3.2 of those standard bet sizes — bankroll-agnostic by design.

A sportsbook is a licensed operator that sets odds and accepts wagers on sporting events. Each book prices markets independently, so the same bet can carry a different number and a different vig at every book on a given night.

Because books disagree, holding accounts at several of them is how a bettor captures the best available price on each play.

Book shopping, or line shopping, is comparing the same bet across multiple sportsbooks to take the best available price. Getting -105 instead of -115 on a bet you'd make anyway is free expected value with zero added handicapping work.

Line shopping is the highest-return habit in betting and requires no model — just accounts at enough books to have a choice.

Injury impact is how much a player's absence or limited status moves a line before the market fully adjusts. A starting quarterback ruled out can swing a spread several points and quietly reshape every teammate's prop projection in the same lineup.

The edge lives in the lag — the window between the news breaking and the book repricing the dependent props.

Weather impact is the effect of wind, rain, cold, or extreme heat on a game's scoring and on individual stat lines. High wind suppresses passing and kicking totals; in baseball it can turn a hitter's park into a pitcher's park and back within a single afternoon.

Wind is the heaviest hitter in outdoor football and baseball totals. Rain matters less than the public assumes once you control for wind.

Situational bias is the systematic distortion in a line caused by schedule and circumstance rather than team strength — back-to-backs, short rest, travel, or a letdown spot after a big win. Books price most of these, but the public over- or under-reacts to the obvious ones.

The reliable edges are the situations the public ignores, not the marquee ones everyone is already betting.

The closing line is the final price a market carries just before the event begins. It is the sharpest number a book will ever post because it has absorbed every dollar, every injury update, and every sharp opinion — which is why it's the benchmark for grading a bet's value.

Beating the closing line repeatedly is the cleanest proof of a real edge, since the close is the market at its most efficient.

Soft markets are bets a book prices loosely because they draw less attention and less sharp money — deep props, secondary leagues, and obscure alternates. The looser the pricing, the more often a fair-line edge appears, since fewer sharp dollars have sanded the number down.

Edges concentrate in soft markets, but so do low limits and slow grading. The pricing is loose precisely because the book doesn't take much action there.