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Betting 101: Odds, Spreads & Totals in Plain English

If -115 looks like a typo and "cover the spread" sounds like a paint commercial, this page is for you. Ten minutes here and every number on a sportsbook — and every number in LineDrift — will make sense.

American odds: what the minus and plus mean

US sportsbooks quote prices as American odds — a number with a minus or plus sign. It's not a rating; it's a price tag:

Odds are probabilities in disguise

Every price converts to an implied win probability. The formula for minus odds is risk ÷ (risk + 100); for plus odds it's 100 ÷ (odds + 100). Some landmarks:

OddsRisk → WinImplied win chance
-500$500 → $100~83% — wins about five times in six
-200$200 → $100~67%
-115$115 → $100~53.5% — essentially a coin flip
-110$110 → $100~52.4% — the standard spread price
+150$100 → $15040%
+300$100 → $30025%

Notice -115 implies ~53.5%, not 50%. That extra few percent is the juice (or "vig") — the sportsbook's built-in fee. It's why both sides of the same coin-flip bet cost -110: the book collects a margin no matter who wins. Beating the juice over time is the entire challenge of betting.

Moneyline: just pick the winner

A moneyline bet is the simplest kind: your team wins the game, you win the bet — margin irrelevant. The catch is the pricing above. Heavy favorites cost a lot (-500 to win $100), while underdogs pay well but lose more often. There's no free lunch: the price is the handicap.

Point spread: the great equalizer

A point spread makes a lopsided game bettable by handicapping the favorite. If the line is Celtics -7.5, the Celtics must win by 8 or more for their backers to win — to "cover the spread." The other side, Lakers +7.5, wins if the Lakers win outright or lose by 7 or fewer.

Why LineDrift lives on spreads: a spread is the market's measurement of how much better one team is. When the live spread swings far from the closing spread mid-game, that's a measurable overreaction — and measurable is what we do. Read What is LineDrift? for the full picture.

Over/Under: betting the total

The total (over/under) ignores the winner entirely. The book posts a combined-score number — say O/U 145.5 in a college basketball game — and you bet whether both teams' points together land over or under it. Totals are also priced around -110 each way. Beyond being bettable themselves, totals are useful context: a 52-point NFL total and a 145-point college basketball total tell you the expected scoring environment — which is why LineDrift's DriftPoint thresholds account for each league's totals.

Live betting: the market that never sits still

Everything above exists during games too. Live (in-play) lines reprice continuously with every score, injury, and momentum swing — a pre-game -500 favorite that falls behind early might be +120 live twenty minutes later. Live markets move fast and, in the chaos, sometimes move too far. That gap between the live number and the considered pre-game number is exactly what LineDrift measures.

The terms, one more time

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Now read What is LineDrift? — it'll click.