# NetArbs > NetArbs compares live odds from 30 sportsbooks and exchanges, removes the vig to find fair odds, and flags +EV player props on PrizePicks, Underdog and more. NetArbs is sports betting analytics software for people who shop lines and bet only when the price is right. ## What it does - **Odds board**: live odds from 30 sportsbooks, exchanges and prediction markets on one screen — moneylines, spreads, totals and player props — with each book's margin removed to show fair odds. - **DFS Studio**: player props on PrizePicks, Underdog, ParlayPlay, Betr, Sleeper, Dabble, DraftKings Pick6 priced against the sharp books; props above the app's break-even are listed with the number of books behind each price. - **Slip builder and bot**: the desktop app builds slips in PrizePicks, Underdog, Betr, Sleeper, DraftKings Pick6 and stops before Submit — the user places every bet. - **Prediction-market arbitrage**: the same contract on Kalshi, Polymarket, Limitless, with fees included. - **Beat the close**: every logged bet is re-priced at its own line until kickoff, to show whether the market moved toward it. ## Coverage - Sports: NFL, college football, NBA, WNBA, college basketball, MLB, NHL, soccer, tennis, esports - Sportsbooks, exchanges and prediction markets: Pinnacle, DraftKings, FanDuel, BetMGM, Caesars, BetOnline, Bet365, Bovada, Hard Rock Bet, Kalshi, Fanatics Markets, Polymarket, Novig, BetRivers, Bally Bet, Betway, Matchbook, MarathonBet, theScore Bet, BetParx, Smarkets, Fliff, ProphetX, Circa Sports, Fanatics Sportsbook, Heritage Sports, Jazz Sports, YouWager, Unibet, Dabble AU - DFS and pick'em apps: PrizePicks, Underdog, ParlayPlay, Betr, Sleeper, Dabble, DraftKings Pick6 ## Free beta - Full access is free while the open beta is active. Create an account, verify your email and download the Mac or Windows app. No card or subscription is required. ## Questions ### What is NetArbs? NetArbs is sports betting analytics software. It compares live odds from 30 sportsbooks, betting exchanges and prediction markets, removes each book's margin (the vig) to estimate fair probabilities, and shows where a price is off the market: +EV player props on DFS pick'em apps, better lines at sportsbooks, and arbitrage between Kalshi, Polymarket and Limitless. ### Which sportsbooks and apps does NetArbs compare? Sportsbooks, exchanges and prediction markets: Pinnacle, DraftKings, FanDuel, BetMGM, Caesars, BetOnline, Bet365, Bovada, Hard Rock Bet, Kalshi, Fanatics Markets, Polymarket, Novig, BetRivers, Bally Bet, Betway, Matchbook, MarathonBet, theScore Bet, BetParx, Smarkets, Fliff, ProphetX, Circa Sports, Fanatics Sportsbook, Heritage Sports, Jazz Sports, YouWager, Unibet and Dabble AU. DFS and pick'em apps: PrizePicks, Underdog, ParlayPlay, Betr, Sleeper, Dabble and DraftKings Pick6. ### Which sports does it cover? NFL, college football, NBA, WNBA, college basketball, MLB, NHL, soccer, tennis and esports — game lines and player props where the books post them. ### How does NetArbs find +EV player props? For each prop it takes the sharp books' prices on the same player, stat and line, removes their margin to get a fair probability, and compares that with the break-even the DFS app's payout requires. Props above break-even are listed in DFS Studio, each with the number of books behind its price. ### Does NetArbs place bets for me? No. The NetArbs desktop app can build a slip in your PrizePicks, Underdog, Betr, Sleeper and DraftKings Pick6 account, but it always stops before Submit: you review the slip and place it yourself. ### How much does NetArbs cost? NetArbs is free during open beta. Create an account, verify your email and download the desktop app without a card. Beta access includes every feature and does not start a subscription. ### Can I use it on Mac and Windows? Yes. NetArbs runs in the browser, and there is a desktop app for macOS and Windows; the slip-building bot runs in the desktop app. ### Does NetArbs guarantee winning bets? No. NetArbs is a research and price-comparison tool. It shows where books disagree with the market; it does not predict outcomes, and every bet carries risk. Bet only where it is legal for you. ## Links - [Home](https://netarbs.com/) - [Free odds board](https://netarbs.com/odds): moneylines, spreads and totals from the big US sportsbooks, refreshed every 10 minutes, no account needed - [NFL odds](https://netarbs.com/odds/nfl) - [NBA odds](https://netarbs.com/odds/nba) - [NHL odds](https://netarbs.com/odds/nhl) - [MLB odds](https://netarbs.com/odds/mlb) - [College Football odds](https://netarbs.com/odds/college-football) - [College Basketball odds](https://netarbs.com/odds/college-basketball) - [WNBA odds](https://netarbs.com/odds/wnba) - [Learning center](https://netarbs.com/learn): worked examples for sportsbook odds, DFS props and prediction markets - [How to remove sportsbook vig from odds](https://netarbs.com/learn/remove-sportsbook-vig): A worked no-vig probability example, the limits of a two-way model, and how NetArbs uses fair prices to compare books. - [What makes a bet positive expected value?](https://netarbs.com/learn/positive-expected-value-bets): Calculate break-even probability and expected value from a price, then see why a model edge still needs fresh lines and enough market support. - [How to price DFS pick’em player props](https://netarbs.com/learn/dfs-pickem-prop-pricing): Compare a pick’em prop with matching sportsbook lines, remove the vig, and account for the app’s payout and slip structure. - [Kalshi and Polymarket arbitrage: a practical checklist](https://netarbs.com/learn/kalshi-polymarket-arbitrage): Understand paired YES/NO prices, exchange fees, settlement mismatch, liquidity and execution risk before treating a spread as arbitrage. - [How it works](https://netarbs.com/how-it-works): line shopping, removing the vig, +EV against a pick'em app's break-even, closing-line value - [Pricing](https://netarbs.com/pricing) - [FAQ and betting terms](https://netarbs.com/faq) - [Desktop app for macOS and Windows](https://netarbs.com/download) - [Privacy](https://netarbs.com/privacy) - [Full text for AI assistants](https://netarbs.com/llms-full.txt) NetArbs is a research and price-comparison tool. It does not predict outcomes or guarantee winnings; bet only where it is legal for you. ## How NetArbs works Source: https://netarbs.com/how-it-works ### The same bet has different prices Sportsbooks set their own odds, so the same moneyline, spread, total or player prop is priced differently from one book to the next. NetArbs collects the prices from 30 sportsbooks, exchanges and prediction markets and lines them up side by side, so the best price on every side is one look away. Taking the best price every time is called line shopping, and it is the cheapest edge in betting. ### The vig, and how it is removed Every price includes the book's margin, called the vig or juice. At -110 on both sides of a bet each side implies a 52.4% chance, 104.8% in total. A fair coin is 50/50; the extra 4.8% is what the book keeps. Removing the vig ("de-vigging") turns the two prices back into probabilities that add up to 100%. On -110/-110 every method gives 50%. Away from even money the methods disagree, because books load more of their margin onto the longshot: at -150/+130, taking the margin off in proportion (multiplicative) puts the favourite at 58.0%, while the power method, which takes more off the longshot, puts it at 58.4%. NetArbs uses the power method by default and lets you switch to additive, multiplicative or the most conservative of the three. ### The fair price comes from the sharp books A fair probability is only as good as the prices it is taken from. NetArbs de-vigs the books that are measured to be accurate on that sport and market, and takes the median across every one of them that quotes the same player, stat and line. Each price shows how many books are behind it. DFS and pick'em apps never set a fair price. Their lines are the offer being judged, not the evidence: a prop is priced from the sportsbooks first, and only then compared with what the app pays. ### +EV on pick'em apps: the break-even A pick'em slip pays a fixed multiple when every leg hits, so each leg has a break-even hit rate. A 2-pick PrizePicks Power Play pays 3x, so each leg must hit 57.7% of the time to break even; a 2-pick on Underdog pays 3.5x, a break-even of 53.5%; a 6-pick PrizePicks Power Play pays 37.5x, 54.7% per leg. A leg is +EV (positive expected value) when its de-vigged fair probability is above that break-even. DFS Studio lists those legs and builds slips from them; the desktop app can fill the slip in your account and always stops before Submit. ### Beating the closing line The closing line, the price just before a game starts, is the market's last and best-informed estimate. A bet placed at a better price than the close was a good price by the market's own final judgement, so closing-line value (CLV) shows whether bets are +EV long before enough results come in to tell skill from luck. Every bet you log is re-priced at its own line until kickoff, to show whether the market moved toward it. ### Prediction-market arbitrage Kalshi, Polymarket and Limitless list many of the same questions. When YES on one and NO on another cost less than $1.00 together, buying both pays $1.00 whichever way it resolves. NetArbs finds those pairs with each venue's fees included, and only where both contracts settle on the same event. ### What it does not do NetArbs does not predict outcomes and does not guarantee winnings: a +EV bet loses often, and the edge only shows over many bets. It never places a bet for you. Bet only where it is legal for you, and only what you can afford to lose. ## Betting terms Source: https://netarbs.com/faq ### What is the vig? The vig (also vigorish, juice or margin) is the bookmaker's built-in edge. At -110 on both sides each side implies 52.4%, 104.8% in total; the 4.8% over 100% is the vig. ### What are no-vig fair odds? The odds left after the vig is removed: the probabilities a market implies once they add up to 100%. On -110/-110 both sides are 50%. On -150/+130 the favourite is 58.0% by the multiplicative method and 58.4% by the power method. ### What is a +EV bet? A bet whose price pays more than its fair probability warrants, so it wins money on average over many bets. On a pick'em app, a leg whose fair probability is above the app's break-even hit rate. ### What is line shopping? Comparing the same bet across sportsbooks and taking the best price. NetArbs's odds board shows 30 books, exchanges and prediction markets side by side. ### What is closing-line value (CLV)? How much better your price was than the market's last price before the game started. Consistently beating the close is the best early sign that bets are +EV. ### Is the free odds board real time? No. The free board shows DraftKings, FanDuel, BetMGM, Caesars, Bet365, BetRivers, Hard Rock Bet and Fanatics Sportsbook and is refreshed every 10 minutes. Real-time odds from all 30 books, fair odds with the vig removed and the +EV lists are in the app, with a 7-day free trial.