Every CS2 bet starts with a number, and most people read it wrong. They see 1.45 on a favorite and think "safe", or 3.20 on an underdog and think "big win". The number is neither. It is a price, and a price is only good or bad compared with how likely the outcome really is. This guide shows how to read that price in every format you will meet, and how to tell when it is worth taking.
Decimal odds
Most esports books and skin sites show decimal odds. The number is your total return for each unit staked, including the stake itself.
- 1.50: a 10 euro bet returns 15 euros. Profit is 5 euros.
- 2.00: a 10 euro bet returns 20 euros. Profit is 10 euros.
- 3.40: a 10 euro bet returns 34 euros. Profit is 24 euros.
Profit is always stake × (odds − 1). Anything under 2.00 means the book sees that side as the favorite. Anything above 2.00 is an underdog price.
American and fractional odds
American odds, also called moneyline odds, are built around a 100 unit bet. A plus sign tells you the profit on a 100 stake. A minus sign tells you how much you must stake to win 100.
- +150: bet 100 to win 150 profit. Decimal equivalent: 2.50.
- -200: bet 200 to win 100 profit. Decimal equivalent: 1.50.
To convert to decimal:
- Positive American odds: (odds ÷ 100) + 1. So +150 becomes 2.50.
- Negative American odds: (100 ÷ odds without the minus) + 1. So -200 becomes 1.50.
Fractional odds such as 6/4 show profit relative to stake. Divide the two numbers and add 1 to get decimal: 6 ÷ 4 = 1.5, plus 1 gives 2.50. You will mostly see fractional odds on UK books, rarely on CS2 sites.
Odds conversion table
The prices you will see most often on CS2 match winner markets, in all three formats:
| Decimal | American | Fractional | Implied probability |
|---|---|---|---|
| 1.25 | -400 | 1/4 | 80.0% |
| 1.50 | -200 | 1/2 | 66.7% |
| 1.67 | -150 | 2/3 | 59.9% |
| 1.80 | -125 | 4/5 | 55.6% |
| 1.91 | -110 | 10/11 | 52.4% |
| 2.00 | +100 | 1/1 (evens) | 50.0% |
| 2.50 | +150 | 3/2 | 40.0% |
| 3.00 | +200 | 2/1 | 33.3% |
| 4.00 | +300 | 3/1 | 25.0% |
Implied probability: the number that matters
Implied probability turns a price into the chance the market is giving an outcome. For decimal odds the formula is one line:
Implied probability = 1 ÷ decimal odds
A team at 1.60 is priced to win 62.5% of the time. That is also your break-even rate. If you bet that price over and over, you need to win more than 62.5% of those bets just to stop losing money. This is why a long run of short-priced favorites can lose even with a decent hit rate. At an average price of 1.45, a 65% win rate still loses, because the break-even point is 69%.
Prediction markets skip the conversion. On Polymarket a contract trading at 62 cents already reads as roughly a 62% chance, which is decimal odds of about 1.61 before fees and spread. Our price to odds converter does this for any contract price, and the Polymarket vs sportsbook guide covers why the two prices often disagree.
Bookmaker margin: why the numbers add up to more than 100%
Take a typical CS2 match: Team A at 1.83 and Team B at 1.95. Convert both:
- Team A: 1 ÷ 1.83 = 54.6%
- Team B: 1 ÷ 1.95 = 51.3%
- Total: 105.9%
One of the two teams will win, so the true probabilities must add to exactly 100%. The extra 5.9% is the overround, the book's built-in edge. To estimate the fair price, divide each implied probability by the total:
- Team A: 54.6 ÷ 105.9 = 51.6%, a fair price of about 1.94
- Team B: 51.3 ÷ 105.9 = 48.4%, a fair price of about 2.07
So the book is paying 1.83 on an outcome that is fairly worth about 1.94. That gap is what you pay to bet. Lower margins mean better prices for you, which is why comparing books matters more than most people think. The no-vig calculator runs this for any two-way or three-way market.
How to tell if a price has value
A bet has positive expected value (EV) when the odds pay more than the true chance deserves. You never know the true chance for certain, so you compare the price with your own estimate:
EV per unit = (your probability × decimal odds) − 1
Say you rate Team B at 55% to win:
- At 1.95: 0.55 × 1.95 − 1 = +0.07, or about +7% per unit staked. Worth considering.
- At 1.80: 0.55 × 1.80 − 1 = −0.01, or −1% per unit. Skip it, even if you think they win.
The second case is the one most bettors get wrong. Picking the likely winner is not enough. If the price is too short, the correct decision is no bet. That is why our daily picks include skip calls and why every posted pick goes into a public results ledger with the odds taken. The odds edge calculator gives you EV and break-even numbers for any price.
Be honest about where your 55% comes from. A gut feeling after watching one match is not an estimate. Map pool overlap, recent results against similar opponents, roster changes, and whether the match is best-of-one or best-of-three all move the real number. Series length alone changes a lot, as the BO1 vs BO3 guide shows.
CS2 market types and how their odds behave
- Match winner (moneyline): who wins the series. The most liquid market and usually the lowest margin.
- Map winner: a single map. Prices depend heavily on whose map pick it is. See the map veto guide for how picks and deciders work.
- Map handicap (-1.5 / +1.5): in a best-of-three, -1.5 means the team must win 2-0. +1.5 means the team must win at least one map. The underdog +1.5 is often priced short because a single map win is likely.
- Total maps (over/under 2.5): over 2.5 wins if the series goes to a third map. Close matchups push this price down.
- Round handicap and total rounds: per-map markets such as -3.5 rounds or over 21.5 rounds. They carry higher margins and react strongly to overtime risk.
Every one of these uses the same maths. Convert the price, compare it with your estimate, and check the margin.
Line movement and closing line value
Odds move between opening and match start as money comes in and news lands: a stand-in, a visa problem, a team resting players. The final price before the match is called the closing line, and it tends to be the most accurate number the market produces.
If you take 1.95 and the match closes at 1.80, you beat the closing line by about 8% (1.95 ÷ 1.80 − 1). Doing that consistently is one of the best signs that your process finds real value, even across losing streaks. Doing the opposite consistently means the market knows something you do not.
Whatever you use to bet, record the price you took, the closing price and the result. Our ledger ROI calculator turns that record into hit rate, ROI and units, and the glossary defines every term on this page.