Hedge, Edge, Arbitrage: Three Sports Calculators and When Each Is Actually Useful

Published 2026-06-12 · Tags: sports, tools, product

Three new calculators in Sports Tools. What each one does, worked examples, and why we deliberately left Kelly staking out.

We added three calculators to the sports tracker this week, under Sports Tools: hedge, edge and arbitrage. They're small, they're fast, and I want to be precise about when each one is worth opening, because "sports betting calculator" is a phrase that gets attached to a lot of nonsense.

Hedge

You have a bet open. The situation changed. You want to know how much to put on the other side so the outcome doesn't matter anymore, or matters less.

Classic case: you took a team at 4.00 pre-match for $100, they're 1-0 up at half time, and the opponent is now 3.50 live. The calculator takes your original stake and odds, the current price on the other side, and returns the hedge stake that gives you the same profit either way (here, about $114 for a locked profit of roughly $186). It also shows partial hedges, because locking everything is often the wrong call; sometimes you want to guarantee your stake back and keep some upside.

What it won't do is tell you whether to hedge. That's a question about how the price moved versus how the probability moved, and it's the hard part. The calculator just removes the arithmetic so you can think about the hard part.

Edge

This one converts odds to implied probability, strips the book's margin out of the market, and compares the fair price to your own estimate.

Example: a two-way market at 1.90 / 1.95. The raw implied probabilities add up to 103.9%, so the book is holding 3.9%. Normalizing gives you the fair probabilities (about 50.6% and 49.4%). If you think the first side is really 55%, your edge on the 1.90 price is about +4.5%. If you think it's 52%, your edge is negative even though you're "right" about the direction.

The point of the tool is that last case. Being right about who's better is not the same as having a bet. You need to be right by more than the margin.

Arbitrage

Two books, two prices, a combined implied probability under 100%. The calculator takes both prices and your total stake and splits it so you profit whichever side wins.

I'll be blunt: you will rarely use this on Stake alone. Arbs exist between books, not within one. Stake's margins are reasonably consistent and their trading team is not asleep. Where this comes in handy is when you hold accounts elsewhere and want to check a line fast, or when a boosted price is actually boosted enough to arb against another book's unboosted price. That happens more than people think during big tournaments, and less than the "arb bot" sellers claim.

Why these three and not twenty

Every calculator we add is one more thing to maintain and one more thing cluttering the page. These three cover the questions that actually come up in chat: "how much do I hedge", "is this price good", "can I lock this in". Kelly staking was the fourth candidate and we left it out on purpose. Kelly needs a probability estimate you trust, and if you had one of those you wouldn't be asking a calculator.

A note on the numbers

All three run in your browser. Nothing is sent anywhere. The odds you type in are whatever format you like (decimal, American, fractional); we convert on the fly.

If a calculation looks wrong, send us the inputs. Rounding on American odds conversion is the usual culprit and we'd rather fix it than argue about it.