About SlateProof

What does SlateProof do?

It reads the odds at every legal US sportsbook and exchange it tracks and publishes four things on the live dashboard:

• Do this now: arbitrage and promo hedges that lock a profit if every bet is accepted at the price shown, with the exact stakes and the accounts each needs.
• Promo plays and sign-up offers: what each sportsbook promotion and new-customer offer is worth, priced against fair prices from sharp books and exchanges.
• Track record: every move the engine flags, frozen the first time it appears and graded after the game.
• Watch list: straight bets that a price screen flags. It is paper only and unproven.

Each figure's method is on the methodology page, and the guides and calculators explain the ideas behind them.

What does SlateProof not do?

• It never places a bet on its own. Every bet is yours to place at the venue.
• It is not a sportsbook or an exchange. It takes no bets, holds no money and moves none between venues.
• It never asks for your sportsbook username or password. Promotions tied to your account are invisible to it, so figures use typical terms and mark any amount a source did not give as assumed.
• It does not promise profit. Prices move, venues limit accounts and void bets, and a bet with positive expected value can still lose.
• It is not financial, tax or legal advice.

There is one exception, and it is your own click. If you create an account and connect an exchange that has an API (Kalshi, Polymarket US or Novig), the dashboard can show a one-click button beside a bet at that exchange. Pressing it sends that exact order as a fill-or-kill limit order at the price shown, from your own browser, with your own key, within your per-order limit. Nothing trades automatically, and the key stays in your browser. What the server does and does not see is on the privacy page. Each exchange's own terms apply to your use of its API; for example, Kalshi limits its API to a member's own trading.

Who is it for?

Adults who already bet legally and want the numbers: how much a promotion is worth, whether two venues disagree enough to lock a profit, and what a fair price looks like. It is not for tips, for anyone who wants income from betting, or for anyone under the legal age. Responsible gambling has the age rules and where to get help.

Whether you can bet at a venue depends on the state you are in when you place the bet. The state hub shows which tracked venues operate where, and the dashboard's “Where you bet” picker hides the venues that are not legal for you. Your choice stays on your device.

Is it free, and how does it make money?

It is free, and it does not earn money today. There are no ads, no affiliate links and no paid placement. That was checked in the site's own code on October 6, 2026: its pages carry no advertising or tracking scripts, and its links to sportsbooks and exchanges go to each venue's own web address with no referral code. Every venue is treated the same in the math, and the board ranks moves by dollars, not by who would pay for a mention.

If that ever changes, this page will change first, and any affiliate link will be labelled where it appears.

Who runs it, and how are the pages made?

SlateProof is operated by its owner, who runs the server and the engine. Pages are published under the SlateProof name; none is written by a sportsbook, an exchange or a sponsor.

Facts that go stale (where each venue is legal, exchange fees, promotion terms) live in dated data files. They are researched from the operators' own pages or, where those cannot be read, from at least two independent trackers, and are not fetched automatically. The page that uses a fact shows the date it was checked. Automated tests check each page's structure and links and, for the privacy policy, that every item the account system stores is listed.

Where does the data come from?

Odds, final scores and box-score statistics come from PropLine on its free plan, which allows 1,000 requests a day. One request returns about thirty books, including sharp books and exchanges. So SlateProof sees snapshots taken minutes apart, not a live feed, and the dashboard shows how old each price is. PropLine carries no Caesars, bet365, ESPN Bet, BetParx, Bally Bet, Circa or Borgata prices, so those books cannot appear here as venues. PropLine's terms forbid bulk redistribution of its data, so the site shows derived figures and never serves raw odds captures.

Where each venue is legal, exchange fees and promotion terms are researched separately and dated. They are listed on the methodology page.

How should I read the figures?

• Locked profit: what an arbitrage or a promo hedge pays if every bet is accepted at the price shown. A limit, a void or a moved line can break it.
• Expected value (EV): the average result per dollar if a bet could be repeated many times at a fair probability that is itself an estimate. Any single bet still wins or loses.
• Paper: a result the engine recorded without anyone betting. It is what the move would have made, not money anyone was paid.
• Frozen: recorded the first time the engine saw it, before the game, and never edited afterwards.
• Assumed: a promotion figure that no source gave. It is marked as assumed.

How are mistakes corrected?

If a fact on a page is wrong, the page is fixed and its Updated date moves; the date changes only when the content does. A decision that the engine has frozen is never edited or deleted. If a grade or a source fact turns out to be wrong, the correction is recorded as a new revision next to the original, so the track record cannot be quietly improved after the fact.

State availability, exchange fees and promotion terms change without notice. Each carries a check date, and your venue's own app or your state regulator has the final say.

A public contact address has not been published yet. When one is, it will be listed here.