Every price on OctopusOdds is shown in American odds — the format you’ll see at every US sportsbook. It looks like a plus or minus sign followed by a number, and once the format clicks, you can read any line on the board in a couple of seconds.

Moneylines

A moneyline is a bet on who wins, with no spread involved. The minus number shows the favorite; the plus number shows the underdog.

  • Negative odds (e.g. −150) show how much you’d need to stake to win $100. At −150, a $150 bet wins $100 (plus your $150 back).
  • Positive odds (e.g. +130) show how much you’d win on a $100 stake. At +130, a $100 bet wins $130 (plus your $100 back).

You can bet any amount — the odds just set the ratio. A $20 bet at +130 wins $26.

Turning a price into a probability

Every price implies a probability, and it’s worth being able to do this in your head:

  • For negative odds: odds ÷ (odds + 100). At −150, that’s 150 ÷ 250 = 60%.
  • For positive odds: 100 ÷ (odds + 100). At +130, that’s 100 ÷ 230 ≈ 43.5%.

Notice those two numbers (60% and 43.5%) add up to more than 100%. That gap is the vig — the sportsbook’s built-in cut, covered in the next guide.

Spreads

A point spread handicaps the favorite so both sides are priced close to even money. −3.5 next to a team means they have to win by 4 or more for that bet to pay out (“cover”); the underdog at +3.5 covers if they win outright or lose by 3 or fewer. The .5 exists specifically so the bet can’t push (tie).

The number attached to the spread (often −110 on both sides) is priced separately from the spread itself, and it moves independently — which is why two books can both offer −3.5 on the same game at different prices.

Totals (over/under)

A total sets a combined-score number for the game, and you bet whether the actual combined score lands over or under it. Same mechanics as a spread — a number, plus a price on each side.

Why half a point (or five cents) matters more than it looks

−3.5 at −105 and −3 at −115 are not the same bet, even though they look similar. The second one includes 3 as a possible outcome (a push), and 3 is the single most common final margin in the NFL. Small differences in the number itself, not just the price next to it, can change what you’re actually betting on — which is the whole reason comparing books line by line, not just price by price, is worth the extra few seconds.