The bestbetting sites.All in one place.

Odds do two jobs at once. They tell you what a winning bet pays, and they tell you what the bookmaker thinks the chance is.

Fractional odds like 5/1 mean you win five pounds for every one you stake, plus your stake back. Decimal odds like 6.0 mean your stake is multiplied by six in total. They are the same price written two ways: 5/1 and 6.0 are identical.

Turn any price into a percentage chance by dividing 100 by the decimal odds. 6.0 becomes 16.7%, 2.0 becomes 50%, 1.25 becomes 80%. That percentage is the implied probability, and it is the single most useful thing to know about a price.

Add up the implied probabilities of every outcome in a market and you will get more than 100%. The amount over 100% is the bookmaker's margin, sometimes called the overround. On a two-way market it might be 4%, on a 20-runner handicap it can be 25%. That margin is how the book makes money, and it is why the odds converter on this page shows the implied chance next to every price.

An each-way bet is two separate bets of the same size: one that your selection wins, and one that it places. A £5 each-way bet costs £10, because you are staking £5 twice.

The win half pays at the advertised odds. The place half pays at a fraction of them, usually a fifth or a quarter, and only if your selection finishes inside the places being paid.

The place terms are what matter and they change race to race. A five to seven runner race normally pays two places at a quarter the odds. Eight or more runners pays three places at a fifth. Handicaps with sixteen or more runners often pay four places at a quarter. Read the terms on the race, not on the last one.

The arithmetic that catches people out: at short odds, an each-way bet can place and still lose you money overall, because the place return does not cover the losing win half. As a rough guide the place half only starts making sense at bigger prices. The bet calculator on this page works out the exact number for any odds and place terms, which is more use than a rule of thumb.

A free bet is not cash. Almost every one has the stake withheld from the return, so a winning £10 free bet at 3.0 pays £20, not £30. That alone removes a third of the headline value.

Then there is the qualifying bet. If the offer needs a £10 stake at minimum odds of 2.0, you have a real £10 at risk before any free bet exists. On average you lose a little of that, because the price you had to take carried the bookmaker's margin.

Expiry and minimum odds on the free bet itself matter too. A seven-day expiry with a 2.0 minimum is a much tighter offer than a 30-day expiry with no odds restriction, even when the headline number is bigger.

The free bet calculator on this page does this properly: it takes the qualifying stake, the free bet amount, the minimum odds and the stake-not-returned rule, and gives you the expected value. It is the number to compare offers on, and it is frequently nothing like the order the headlines suggest.

Decide what the money is before you bet it. A set amount per month that you would otherwise have spent on something enjoyable, and that you will not top up, is a budget. Whatever is in your current account is not.

Keep the stake size consistent. Chasing a losing day with a bigger bet is the single most reliable way to turn a small loss into one that matters, and every bookmaker's business model quietly depends on people doing it.

Write down what you actually bet. Almost everyone remembers their winners more clearly than their losers, so the felt result and the real result drift apart fast. The bet tracker on this page keeps a running total in your own browser, and the number it shows is usually a surprise.

Use the tools the operators are required to give you: deposit limits, time-outs and reality checks, all set from inside your account. If betting has stopped being entertainment, GAMSTOP blocks every GB-licensed site at once, and GamCare will talk to you for free on 0808 8020 133.