Both-sides bets: ahead whoever wins
Bet each side at a different betting site. Whoever wins, you come out ahead, if every bet goes through.
4 min readChecked on Oct 31, 2026
A both-sides bet (also called an arb, short for arbitrage) is a bet on every result of one game. Each bet goes to a different betting site (sportsbook). The prices are good enough that you make money whoever wins.
It works because sites set their prices on their own. Sometimes one site is slow to move. Sometimes two sites just disagree. Then the best price on each side can add up to less than 100%.
Prices are chances in disguise
Every price says how likely the site thinks something is. Decimal odds of 2.00 mean 50%. You get $2 back for every $1 if it wins. The chance a price means is 1 divided by the decimal odds. A price of 2.20 means 45.45%, and 2.10 means 47.62%.
At one site, the sides of a game always add up to more than 100%. The extra is the site's cut (also called the hold). Two sides at 1.91 add up to 104.71%. So the site keeps about 4.7% on top of the fair chances.
A both-sides bet is the rare case where the best prices add up to less than 100%. Each price comes from a different site.
Chance a price means = 1 / decimal oddsSum = 1 / odds A + 1 / odds B (+ 1 / odds C)It is a both-sides bet when the sum is under 100%Profit % = 1 / sum - 1Amount on a side = total x (1 / its odds) / sumA two-way both-sides bet
- Site A has team 1 at 2.20 (45.45%). Site B has team 2 at 2.10 (47.62%).
- Added up: 45.45% + 47.62% = 93.07%. That is under 100%.
- Profit %: 1 / 0.9307 - 1 = 7.44%.
- With $1,000 in total, bet $488.37 on team 1 at Site A. Bet $511.63 on team 2 at Site B.
- If team 1 wins: $488.37 x 2.20 = $1,074.41 back. If team 2 wins: $511.63 x 2.10 = $1,074.42 back.
About $74 profit whoever wins, if both bets go through. Real ones are usually much smaller. Big gaps between sites close fast. A very big one is often a mistake in one price.
What can go wrong
A both-sides bet only makes money if every bet goes through at the price you saw. Here is what can break it:
- The price moves. You place Bet 1. Then the other site changes its price before you place Bet 2. Now you hold one bet on its own. This is the most common problem.
- A bet is cancelled or cut. A site can cancel a bet at an obvious mistake price. Sites call this a palpable error. A site can also take only part of your amount.
- The bets don't match. Rules differ between sites, like whether overtime counts. Every bet has to settle on exactly the same result.
- A typing mistake. A wrong amount, or a bet on the wrong side, turns it into an ordinary bet.
That is why WynFynd always says you come out ahead if every bet goes through. It is not money you already have.
How to place one
- Check that both prices are still there and still add up to under 100%. The both-sides calculator does this for you.
- Place the bet most likely to move first. On a WynFynd alert that is Bet 1. It is usually the price furthest above the other sites.
- Place Bet 2 straight away. If its price moved, check again. Another site may still pay enough.
- If no site does, locking in a small loss can be better than one bet on its own.
- Log both bets, so your results and the money at each site stay right.
Rounding. Amounts like $488.37 stand out to a site. Round each one to $5: here $490 and $510. You still make $78 if team 1 wins and $71 if team 2 wins.
Three-way bets
Soccer and some other sports have three results: home, draw and away. The math is the same with three prices. Add up 1 / odds for all three. If the total is under 100%, you bet all three, often at three sites.