Betting 101
A practical guide to many of the terms used throughout this site and in the sports gambling world
Odds
Odds describe the tradeoff between risk and reward. Most commonly you will see odds in American format or decimal format.
Stake and Payout
The stake is the amount you put at risk. Payout refers to what is paid out to you in a winning wager including your original stake.
Let's say you made a $10 wager at odds +200. The stake is then $10. If the bet loses, you lose the stake. If the bet wins, your profit would be $20 and the payout from the winning wager would be $30.
Market Types
A market is the specific question you are betting on. This means the same game can offer several markets.
Hedge
Hedging means placing another bet or trade that reduces the risk of an existing position. In combination with the use of a promotion, immediately hedging a bet can guarantee a profit.
Parlay
A parlay is one wager made up of multiple bets, or what gamblers call legs. Every leg must win for the parlay to win. If a wager contains just one bet, it is called a straight wager.
Parlays are popular because they create large payouts from small stakes. They are also dangerous because the book's edge compounds across legs, and one bad leg can sink the whole ticket. Many times a sportsbook may offer a 33% profit boost on a 3+ leg parlay, but beware this is not the profit opportunity it appears to be as perfect hedging can still struggle to break even in these scenarios.
Vig
Vig, short for vigorish, is the sportsbook's built-in margin. It is the reason two opposite sides of a market usually add up to more than 100% implied probability.
A standard two-sided market at -110/-110 is the classic example. Both sides have equal odds, but the bettor must risk $110 to win $100 if they bet either side. That margin is how the book makes money over time. When you compare prices across different betting platforms for the same market, you can reduce vig greatly. For example, assume DraftKings offers one NBA moneyline matchup at odds -120/+100 while FanDuel offers the same NBA moneyline matchup at odds -110/-110. Taking the best prices across just two sportsbooks, you effectively can get odds -110/+100, greatly reducing the vig you actually experience as a better.
Contracts
Exchange-style markets like Polymarket operate via trading binary contracts directly against each other using an open order book. Prices fluctuate purely based on organic supply and demand. Instead of taking a posted sportsbook line, you are buying or selling a binary contract that resolves to Yes or No.
These contracts are quoted in cents. A Yes contract being offered at 63ยข means that it will cost that much to buy it. If the market resolves to yes, it pays $1. If it resolves no, it pays $0 and the person who sold you the contract will receive $1. Assuming no fees, this yes contract is effectively available at odds -170.
Maker & Taker
On exchange markets, traders buy and sell directly with one another rather than betting against a sportsbook. The amount of money available to trade at different prices is known as liquidity. A market with strong liquidity has substantial buy and sell interest near the current price, making it easier to enter or exit positions without significantly moving the market.
When trading on an exchange, you can either accept an existing price or post your own order. If you accept someone else's open offer, you are a taker because you remove available liquidity from the market. If you place an order that remains available for others to accept, you are a maker because you add liquidity to the market.
Many exchanges treat those two actions differently when determining fees. Kalshi charges lower fees for makers while Polymarket actually rewards makers.
As trade sizes increase, a taker may consume all of the available liquidity at the best price and begin filling at worse prices. As a result, a small trade may receive the displayed price, while a larger trade may receive a worse average fill.
Pushes & Voids
- FanDuel returns bonus bets for voided wagers but not pushed ones
- DraftKings returns bonus bets for both pushed and voided wagers
- BetMGM returns bonus bets for both pushed and voided wagers. The first-bet insurance promotion seems to follow the same pattern given that it is only considered on a qualifying bet
- theScore returns bonus bets for both pushed and voided wagers. The first-bet insurance promotion seems to follow the same pattern given that it is only considered on an eligible wager
- Bet365 returns bonus bets for voided wagers but not pushed ones. The first-bet insurance promotion is not returned in the event of a push or void on a first bet
- Prime Sportsbook returns bonus bets for voided wagers but not pushed ones
- Exchanges like Kalshi and Polymarket differ materially from traditional sportsbook settlement. In fact, they typically treat a voided market and a pushed market in the same manner. Polymarket will settle binary $1 contracts 50/50 which means each contract will split its payout between the Yes and No sides. Hence, if a market voids and you bought the contract as a favorite, you will lose some money. Meanwhile, if you bought it as an underdog, you will make a little money. On Kalshi, the wager will resolve at a stated fair market price rather than being voided. This gives Kalshi considerably more discretion, making settlement outcomes less predictable for bettors.
Arbitrage
Arbitrage betting is a strategy where a bettor places wagers on all possible outcomes of a sporting event across different platforms to guarantee a profit regardless of the result. It capitalizes on market inefficiencies and price discrepancies rather than relying on sports knowledge or luck.
Friend Referral
- Friend referrals can provide benefits such as bonus bets, profit boosts, or site credit. Depending on the platform, these rewards may be given to both the referrer and the referee or only to the referrer.
- Some sportsbooks allow a friend referral to replace the standard new-user promotion. If the referral offer is less valuable than the normal welcome promotion, it is generally better not to use the referral.
- Friend referrals are typically shared through either a referral code or a referral link. When using a referral link, begin the registration process through that link and avoid registering directly on an app, as doing so may prevent the referral from being tracked.
- See the specific sportsbook attack strategy in the Map tab for guidance on when using a friend referral is advantageous during the registration process.
Promos
Sportsbook promotions generate value by artificially enhancing the expected return of a wager. While the vig built into betting markets normally causes fully hedged positions to lock in a small loss, promotions can more than offset this cost, allowing bettors to convert otherwise negative-return wagers into profitable ones.