-870 Odds Explained
- Decimal
- 1.11
- American
- -870
- Fractional
- 10/87
- Implied probability
- 89.69%
- Polymarket
- 90¢
- $100 wins
- 11.49
- American
- -870
- Fractional
- 10/87
- Implied probability
- 89.69%
- Polymarket
- 90¢
- Profit
- 11.49
- Total return
- 111.49
1.115 decimal, -870 American, 89.69% implied probability
-870 is an American price:
the minus sign marks a favourite, and the number is the stake needed to win 100
. Every other format describes the same chance: 1.11 decimal, 10/87 fractional, 89.69% implied probability, 90¢ on Polymarket.
What -870 pays
A 100 stake at -870 returns 111.49 in total: your 100 back plus 11.49 profit. To win exactly 100 you would stake 870.00. The table covers the stakes people actually use.
| Stake | Profit | Total return |
|---|---|---|
| 10 | 1.15 | 11.15 |
| 25 | 2.87 | 27.87 |
| 50 | 5.75 | 55.75 |
| 100 | 11.49 | 111.49 |
| 500 | 57.47 | 557.47 |
| 1,000 | 114.94 | 1,114.94 |
Break-even and long-run results
The implied probability of -870 is 89.69%, and that number is also the break-even win rate: win more often than 89.69% of the time at this price and you profit in the long run, win less often and you lose. The table shows the return on stake at a few win rates, including the break-even rate itself.
| Win rate | Return on stake |
|---|---|
| 50% | -44.3% |
| 55% | -38.7% |
| 60% | -33.1% |
| 65% | -27.5% |
| 90% | 0.3% |
At 89.69% this is a heavy favourite. Prices this short appear when one side is expected to win comfortably: a top seed against a qualifier, a strong home team against a relegation candidate, or a moneyline in a game with a double-digit spread. The catch is the payout. You need to win more than 89.69% of these bets just to stand still, and one loss wipes out several wins.
The vig at -870
If both sides of a two-way market were priced at -870, the implied probabilities would add up to 79.38% above 100%. That excess is the overround, or vig; as a share of stakes it is a 44.25% margin for the bookmaker. Removing it leaves fair odds of 2.00 decimal ( +100) on each side. Use the devig calculator to do the same for any market.
-870 on a betting exchange
Exchanges charge commission on net winnings, so the price you see is not the price you get. At 2% commission -870 is worth 1.113 decimal (-888 American); at 5% it drops to 1.109 (-916). Those are the bookmaker prices you would need to beat.
| Commission | Effective decimal | Effective American | Break-even |
|---|---|---|---|
| 2% | 1.113 | -888 | 89.88% |
| 5% | 1.109 | -916 | 90.16% |
Same price in other formats
Nearby prices
Nearby prices
Frequently asked questions
What does -870 mean in betting?
-870 is an American price. Positive numbers show the profit on a 100 stake; negative numbers show the stake needed to win 100. At -870 the implied probability is 89.69% and a 100 stake returns 111.49.
What is -870 in decimal odds?
-870 converts to 1.115 in decimal odds (usually shown as 1.11). Decimal odds are the total return per unit staked, so multiply your stake by 1.115 to get the return.
What is -870 as a fraction?
-870 is 10/87 in fractional odds, the traditional bookmaker notation where the top number is profit and the bottom number is stake.
How much do I win on a 100 bet at -870?
A 100 stake at -870 wins 11.49 in profit and returns 111.49 including the stake. To win exactly 100 you would stake 870.00.
What win rate do I need at -870?
The break-even win rate equals the implied probability, 89.69%. Winning more often than that at this price is profitable over the long run; winning less often loses money.