What is a surebet?
A surebet, also called an arbitrage bet, is a set of bets on every outcome of one market, placed at different bookmakers, at odds high enough that each outcome returns more than the total staked. It appears when bookmakers disagree on a price, and it lasts until one of them moves.
The test is one line of arithmetic: add up 1 divided by the odds of each outcome. A sum under 1 is a surebet. At 2.10 and 2.05 on the two sides of a match the sum is 0.476 + 0.488 = 0.964, so 100 staked across both returns 100 / 0.964 = 103.73 on each side at those odds.
How the stake for each bet is worked out
Each stake is the total times 1 over its odds, divided by the sum of 1 over every price. Every outcome then returns the same amount: the total divided by that sum.
stake = total x (1 / odds) / sum of (1 / odds)
| Outcome | Odds | Stake | Returns |
|---|---|---|---|
| Home | 2.50 | 42.51 | 106.28 |
| Draw | 3.60 | 29.52 | 106.27 |
| Away | 3.80 | 27.97 | 106.29 |
| Profit | +6.27 | ||
| Outcome | Odds | Stake | Returns |
|---|---|---|---|
| Home | 2.10 | 49.40 | 103.74 |
| Away | 2.05 | 50.60 | 103.73 |
| Profit | +3.73 | ||
Which markets pair into a surebet
The bets have to cover every result between them and be settled by the same rule at each bookmaker. In football that is 1X2 with each outcome at its best price, Over and Under on one line, 1 against X2, 1X against 2, and Asian handicap -0.5 against +0.5, all on the 90 minute result.
A quarter line such as Asian handicap -0.25 splits the stake over two lines, so a draw settles half the bet as lost and returns the other half. Asian handicap quarter lines sets out every case. Over 2.5 at one bookmaker against Under 3.5 at another is a middle, where exactly 3 goals wins both bets.
Football markets are settled on 90 minutes plus stoppage time unless the market names extra time or penalties, so two prices on the same match only pair when both say 90 min. Does extra time count in football betting? covers the cup ties where it matters.
Some bookmakers settle basketball without overtime by default, so pair only markets labelled incl. overtime. The 1X2 on regulation time is a 3-way market that ends before overtime, and it pairs only with other regulation prices.
Hong Kong, Malay and Indonesian odds
Asian bookmakers print the same price in several ways. Hong Kong odds are the winnings on 1 staked, so a Hong Kong price plus 1 is the decimal price, while Malay and Indonesian odds turn negative on one side of evens.
A positive Malay price is the winnings on 1 staked and a negative one is the stake that wins 1, so Malay odds run from -1.00 to 1.00. Indonesian odds are the American price divided by 100.
| Decimal | Hong Kong | Malay | Indonesian | American |
|---|---|---|---|---|
| 1.50 | 0.50 | 0.50 | -2.00 | -200 |
| 1.80 | 0.80 | 0.80 | -1.25 | -125 |
| 2.00 | 1.00 | 1.00 | 1.00 | +100 |
| 2.50 | 1.50 | -0.67 | 1.50 | +150 |
| 3.00 | 2.00 | -0.50 | 2.00 | +200 |
Hedging a bet you already placed
A hedge is a bet on the other side of a bet you already hold, sized so that both results return the same. It is the stake arithmetic with one stake fixed: 20 at 2.10 on the home side is covered by 21.54 at 1.95 on the away side, and both results then return 42.00.
When the other side's price has lengthened since the first bet, both results return more than the two stakes at those odds; when it has shortened, the same arithmetic shows what the cover costs.
Dutching
Dutching spreads one stake over several outcomes of a market so that each of them returns the same amount. When the outcomes cover the whole market and the sum of 1 over their odds is under 1, a dutch is a surebet.
The profit of a surebet can also sit on the outcomes you choose, with the others returning the total staked. At 2.50, 3.60 and 3.80 on a 1X2 with all of the profit on the home win, 100 staked returns 114.75 on a home win and 100.01 or more on a draw or an away win.
Surebet questions
What is the difference between a 2-way and a 3-way surebet?
A 2-way surebet covers a market with two outcomes, such as Over and Under on one line or a basketball match winner incl. overtime. A 3-way surebet covers home, draw and away, so 1 divided by each of its three prices has to add up to less than 1.
Does overtime count in a basketball surebet?
The 2-way match winner is settled incl. overtime, and totals and handicaps count overtime where the market is labelled incl. overtime. The 1X2 on regulation time ends before overtime, so it pairs only with other regulation prices.
Why does rounding the stakes change the profit?
Rounded stakes no longer split the total by 1 over each price, so each outcome returns a slightly different amount and the lowest return sets the profit. At 2.10 and 1.95 on 100, whole stakes of 48 and 52 make +0.80 on the worst outcome, where stakes to the cent make +1.11. When no rounding at a unit keeps a profit, the calculator offers the largest unit that does.
How do tax and commission change the stakes?
A tax or a commission lowers what a bet pays or raises what it costs, so the stakes are worked out again on what each bet keeps. With 5% taken from every deposit and 5% from every withdrawal, 2.10 and 1.95 on a 100 deposit return 91.25 on either result once both taxes are paid.
What if a price changes before I place the other bet?
Work the stakes out again at the new price before you place the next bet, with the stake you already placed fixed. A price that has dropped makes the cover cost more, and the returns show whether each result then pays back more than the total staked.
