Decimal odds in one line
Most sites show decimal odds, such as 1.80 or 2.50. The number is what a winning bet returns for every 1 staked, stake included. A 10 bet at 2.50 returns 25 if it wins: 15 profit plus the 10 back.
The same number tells you the chance the bookmaker is pricing in. Divide 1 by the odds: 1 / 2.50 = 0.40, so a 2.50 price implies a 40% chance. A 1.80 price implies about 55.6%, and 2.00 is exactly 50%.
Why the three prices of a match add up to more than 100%
Take a match priced 2.10 for the home win, 3.40 for the draw and 3.50 for the away win. The implied chances are 47.6%, 29.4% and 28.6%. They add up to 105.6%, not 100%.
The extra 5.6 points is the bookmaker's margin, sometimes called the overround. It is the price of taking the bet. To see the bookmaker's real opinion, divide each implied chance by the total: 47.6 / 105.6 gives about 45% for the home win, 27.8% for the draw and 27.1% for the away win.
Short prices and long prices
A short price (1.30, say) implies a high chance, about 77%, but it pays little, and one loss wipes out several wins. A long price (6.00) implies about 17%, pays a lot and loses most of the time. Neither is good or bad on its own; what matters is whether the chance is higher or lower than the price suggests.
That gap is what bettors call value. If you think a team wins four times in ten (40%) and the price is 3.00 (33% implied), the price is longer than your view says it should be. If your view is wrong, there is no value, however long the price looks.
What to look at next to the odds
On every prediction page you will find the odds beside the chance they imply, the recent form of both teams and the record of the market. Use them together: a 1.45 price on over 1.5 goals is a claim that at least two goals come about seven times in ten, and the form and goals records tell you whether that sounds right for these two teams.
Betting involves real risk and no prediction is a certainty. 18+ only; bet only what you can afford to lose.