Science Of Speculation

UK edition

Launching soon

FACTS not OPINIONS

A free UK odds site that tells you whether a price is good value, not just which bookmaker is biggest.
Every price comes with its fair price and a plain "% chance", so anyone can understand the odds.

Toss a coin: what SOS is about · 45s · AI-generated
Read the transcript

Toss a coin: a fifty-fifty chance. The fair price is evens. £10 gets you £20 back. Now your bookmaker offers 2.1. Is that good? £10 now gets you £21. A pound more, same chance. You'll still lose about half the time. But you're paid more than the chance deserves. That's value. That's what SOS does: our fair price, against your bookmaker's. When their price beats ours, SOS goes green, and we flag it to you the moment it happens. That's where to look for value. Follow us. Coming soon.

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What SOS does

YellowThe fair priceUK bookmakers' prices with each one's margin removed, giving a fair price and its % chance.
GreyThe best priceThe best price from the UK-licensed bookmakers we show, exactly as they show it, with what £10 returns.
Green flagAlertsWhen grey goes more than 1% above yellow, the price turns deep green: a green flag, with the exact time it happened. Switch on alerts to hear a chime.
Value Flag TrackerEvery flag recorded in public with its time, then scored against the final price: green or red. Misses included, nothing deleted.
The SOS DailyYesterday's results and today's games, every price against the SOS fair price, on one page every morning.
Time OutSafer gambling built in: a pre-bet checklist, deposit-limit guidance and short wellbeing breaks.

Quick answers

What is the SOS fair price?

The SOS fair price is what a bet is really worth. We take every UK bookmaker's prices for the event and remove their profit margin (the overround), which leaves a fair price and its % chance. It is shown in yellow.

What is a green flag?

A green flag appears when the best price from the bookmakers we show goes more than 1% above the SOS fair price. That means the bookmaker is paying more than the chance deserves. The price turns deep green, with the exact time it happened.

Does a green flag mean the bet will win?

No. A green flag is about value, not winning. The chance of the result stays the same; the price is simply better than fair. Only the final price, just before the start, shows whether it really was good value.

What is overround?

Overround is the profit margin a bookmaker builds into its prices. On a fair coin toss the fair price is evens (2.0), but a bookmaker might offer 1.9 on each side. The difference is their margin.

What is the Value Flag Tracker?

A public record of every green flag SOS raises, logged with its time before the start and then scored against the final price: green if it beat it, red if it did not. Misses are included and nothing is deleted.

Is SOS a bookmaker?

No. Science Of Speculation publishes information about prices. We do not take bets, and it is not betting advice. We link only to UK-licensed bookmakers. 18+.