The same CS2 match often shows a different price on Polymarket than at a sportsbook. Comparing the two headline numbers tells you very little, because each venue hides its cost in a different place. This page puts both on the same footing, with every number worked through, and then covers the parts that are not about price: what happens when a match is canceled, how much you can get on, and whether you can use either one where you live.
Two pricing models
- Sportsbook: the book sets both prices and takes the other side of your bet. Its margin is built in, so the implied chances of the two teams add up to more than 100%. You see one price per side and pay nothing else.
- Polymarket: other users set the prices on an order book. Each share pays $1 if its team wins. You pay the ask to buy now, and on CS2 markets a taker fee of 0.05 x shares x price x (1 − price) on top. Orders that rest on the book and get filled later pay no fee.
So the fair comparison is the sportsbook price against the Polymarket price after fee, side by side. To see how much margin a book is charging, remove it with the no-vig and hold calculator.
A worked side-by-side
Team A plays team B in a BO3. The prices below are an illustration, but they are in the range you see on a tier-one CS2 match.
The sportsbook: 1.75 on team A, 2.10 on team B
- Implied chances: 1 / 1.75 = 57.1% and 1 / 2.10 = 47.6%. Total: 104.8%.
- The 4.8% above 100% is the overround. Measured as hold, the share of all money staked that the book keeps on a balanced book, it is 1 − 1 / 1.048 = 4.5%.
- Divide each implied chance by 1.048 to remove the margin: team A 54.5%, team B 45.5%. As odds, the no-vig fair prices are 1.83 and 2.20.
Polymarket: team A bid 55¢, ask 57¢
The two sides mirror each other, so team B's ask is $1 − 55¢ = 45¢ and its bid is 43¢. The spread is 2¢ and the midpoint gives team A 56%.
- Team A, taker: 100 shares at 57¢ cost $57.00. Fee: 0.05 x 100 x 0.57 x 0.43 = $1.23. Total $58.23 for a $100 payout, so the odds are 100 / 58.23 = 1.72 and you break even at 58.2%.
- Team B, taker: 100 shares at 45¢ cost $45.00. Fee: 0.05 x 100 x 0.45 x 0.55 = $1.24. Total $46.24, so the odds are 2.16.
- Limit orders: bid 56¢ on team A or 44¢ on team B and wait to be filled. No fee, so the odds are 1 / 0.56 = 1.79 and 1 / 0.44 = 2.27, if the order fills.
For US users on Polymarket US, the taker coefficient is 0.0695 since October 1, 2026, which turns the same two prices into 1.70 and 2.14. Kalshi's 0.07 taker fee on CS2 contracts, rounded up to the next cent, gives the same 1.70 and 2.14.
| Price you get | Team A | Team B |
|---|---|---|
| Sportsbook | 1.75 | 2.10 |
| Sportsbook, margin removed | 1.83 | 2.20 |
| Polymarket, taker after fee | 1.72 | 2.16 |
| Polymarket, limit order filled | 1.79 | 2.27 |
| Polymarket US or Kalshi, taker | 1.70 | 2.14 |
What the numbers show
- Neither venue is cheaper on both sides. Backing team A, the sportsbook pays 1.75 against Polymarket's 1.72. Backing team B, Polymarket pays 2.16 against 2.10. You only find that out by doing the maths for the side you want.
- The total cost here is similar. Buying both sides on Polymarket at the ask with fees costs $1.045 per $1 of payout, or 4.5%. The book's overround is 4.8%. With a 1¢ spread, Polymarket would drop to about 3.5%; with a 10¢ spread on a thin market it would be far worse than the book.
- Patience is the cheapest option. A filled limit order beats the sportsbook on both sides here. The cost is uncertainty: your order may not fill, or may fill only because news has moved the price against you.
- The two venues disagree about the match. The book's fair line has team A at 54.5%, Polymarket's midpoint at 56%. A gap like this is information, not free money. Check lineups and news before deciding which number is stale.
To convert any Polymarket price into decimal or American odds, use the Polymarket odds converter. The basics of implied probability and margin are in our guide to reading CS2 odds.
Settlement differences
Price is only half the comparison. The other half is what happens when a match does not finish normally, and here the three models really differ.
| Situation | Typical sportsbook | Polymarket |
|---|---|---|
| Match canceled | Void, stake back | 50-50: $0.50 a share |
| Walkover before play | Void, stake back | 50-50 |
| Postponed | Void if not played within 48 hours | 50-50 if not rescheduled within 14 days |
| Forfeit after play starts | Varies by book | Awarded team wins |
The sportsbook column follows published esports rules such as Sky Bet's, which void bets on a walkover and on events not completed within 48 hours of the scheduled start. Every book writes its own rules, so read them. The Polymarket column comes from the rules printed on current CS2 match markets, which use HLTV as the resolution source; older markets used a 7-day postponement window instead of 14.
In our example, a canceled match costs the team A buyer $58.23 for $50.00 back, a loss of $8.23. The team B buyer paid $46.24 and gets $50.00, a gain of $3.76. At the sportsbook both would simply get their stake back. Kalshi and Polymarket US use a third method: the exchange settles at its "last fair price" at the time of the announcement, which is close to where the market was trading.
Timing differs too. Polymarket results are proposed through UMA's oracle with a two-hour challenge window, and a disputed result can take several days to settle. A sportsbook usually settles once its results feed updates.
Liquidity and limits
A sportsbook decides how much it will accept from you. It sets a maximum stake per market, and its terms usually let it lower that maximum for individual accounts. Check the terms of any book you use.
Polymarket has no house limit because there is no house. Your limit is the order book: what is offered at the ask, then the next price, and so on. On a big ESL Pro League or Major match that is usually enough for a recreational stake at the quoted price. On a tier-three qualifier the book can be empty or show a spread of 30¢ or more, and buying at the ask there is a bad trade before the match even starts. Kalshi's esports contract terms set a position accountability level of $25,000 per outcome per member, a size at which the exchange can review a position.
Selling before the match
On Polymarket your shares can be sold at any time before the market closes. Suppose you bought 100 team A shares at 57¢ for $58.23 including the fee, and news before the match pushes the bid to 65¢. Selling as a taker returns $65.00 minus a fee of 0.05 x 100 x 0.65 x 0.35 = $1.14, so $63.86. That locks in $5.63 without waiting for the result. The same works in reverse if the price falls.
Many sportsbooks offer cash-out too, but the book sets that price and can decline to offer it. On an exchange you see the bid and the depth, and you choose whether to hit the bid or wait with a limit order.
Access and legality
- Sportsbooks need a license where you live, and the rules differ by country and, in the US, by state.
- Polymarket's international site blocks the US, the UK, France, Germany, Italy, the Netherlands, Belgium, Australia and other countries, plus four Canadian provinces. Using a VPN to get around it breaks the terms. Where it is available, you can open a Polymarket account here.
- In the US, Polymarket US and Kalshi are CFTC-regulated exchanges that require identity verification. Several states have challenged sports event contracts in court, and federal appeals courts have split on the question, so availability can change. Kalshi also accepts users from many countries outside the US; if it accepts yours, you can sign up for Kalshi here. Our Kalshi vs Polymarket comparison covers both in detail.
Whichever venue you use, a lower cost only helps if your read on the match is better than the price. Our own picks come from SkinBetHub's proprietary signal model, built on prediction-market data, are posted with their odds before the match starts, are graded at a flat 1 unit, and every result stays on the results page. None of that guarantees a profit, so stake only what you can afford to lose.