How to Read Esports Odds

Three formats, one meaning

Odds express two things at once: how much a winning bet pays, and how likely the bookmaker thinks the outcome is. The format changes by region, but every format can be converted to the others and to a probability. Use the odds converter to switch between them instantly, but you should also be able to do it in your head.

Decimal odds

Decimal is the standard in Europe and most esports bookmakers. The number is your total return per unit staked, stake included.

• Stake 10 at 1.50: return 15, profit 5.
• Stake 10 at 2.00: return 20, profit 10.
• Stake 10 at 3.40: return 34, profit 24.

Anything under 2.00 is a favourite; anything over 2.00 is an underdog.

Fractional odds

Common in the UK. The fraction is profit over stake. At 5/2 you win 5 for every 2 staked, so a 10 stake profits 25 and returns 35. To convert to decimal: divide the fraction and add 1. 5/2 = 2.5 + 1 = 3.50. 1/2 = 0.5 + 1 = 1.50.

American odds

Used in the United States. Positive numbers show profit on a 100 stake; negative numbers show how much you must stake to profit 100.

• +150: stake 100, profit 150. Decimal 2.50.
• -200: stake 200, profit 100. Decimal 1.50.

Conversion: for positive odds, decimal = (American / 100) + 1. For negative odds, decimal = (100 / absolute American) + 1.

Implied probability

Implied probability is the chance the odds suggest an outcome has. For decimal odds the formula is 1 divided by the odds.

Decimal	Fractional	American	Implied probability
1.25	1/4	-400	80.0%
1.50	1/2	-200	66.7%
1.80	4/5	-125	55.6%
2.00	1/1	+100	50.0%
2.50	3/2	+150	40.0%
3.40	12/5	+240	29.4%
5.00	4/1	+400	20.0%

This number is the whole game. If you believe a team wins more often than the implied probability, the bet is worth taking. If not, it is not, no matter how much you like the team.

The margin

Add up the implied probabilities on every outcome of a market and you will get more than 100 percent. The excess is the bookmaker's margin, also called the overround or vig.

Worked example, a two-way match-winner market:

• Team A at 1.65: implied 60.6%.
• Team B at 2.30: implied 43.5%.
• Total: 104.1%. Margin is 4.1%.

A fair market would sum to exactly 100 percent. The higher the margin, the more you pay for every bet you place, whether you win or lose. Top-tier CS2 and LoL matches often carry margins around three to six percent. Tier-2 events and smaller games such as MLBB can run much higher. Compare the same match across several sites from the bookmaker rankings and you will see the difference immediately.

Removing the margin to find the fair price

Divide each implied probability by the total. Team A: 60.6 / 104.1 = 58.2%. Team B: 43.5 / 104.1 = 41.8%. Those are the bookmaker's actual estimates once the margin is stripped out. Fair decimal odds would be 1.72 and 2.39.

Reading odds movement

Odds open at one price and move as money arrives and news breaks. A favourite drifting from 1.50 to 1.70 before a match usually means a roster or stand-in issue, a patch concern, or sharp bettors backing the other side. Check the team page and the match center for lineup notes before assuming the market is wrong.

Worked example end to end

A best-of-three has Team A at 1.45 and Team B at 2.75. Implied probabilities are 69.0% and 36.4%, total 105.4%, margin 5.4%. Fair probabilities are 65.5% and 34.5%. You have watched both teams on the current patch and think Team B is closer to a 42 percent shot because of a strong map pool. At 2.75, a 42 percent win rate returns 1.155 per unit staked on average, which is a positive expected value of 15.5 percent. That is a bet. If you thought Team B was a 33 percent shot, the expected return would be 0.91 per unit and you would pass.

That process, estimate, compare, bet only when your number beats the bookmaker's, is explained further in the value betting guide.

18+ only. Gamble responsibly. Bet only what you can afford to lose, set deposit limits, and use self-exclusion tools if betting stops being fun.