Scanner book counts: why the number of sportsbooks can mislead

A scanner's book count is the number of books it says it pulls prices from: RebelBetting advertises 120+ bookmakers, OddsJam 150+ sportsbooks and exchanges, Bet Hero 400+ sportsbooks and BetBurger 600+ bookmakers.^[1][2][3][4] Those counts are vendor-reported (checked Oct. 28, 2026). None of them tells you how many of those books you can legally bet at where you live.

Coverage, as each vendor states it (vendor-reported)

Feature	RebelBetting	OddsJam	Bet Hero	BetBurger
Sportsbook coverage	120+ bookmakersVendor-reported	150+ sportsbooks and exchangesVendor-reported	400+ sportsbooksVendor-reported	600+ bookmakersVendor-reported
	RebelBetting website	OddsJam website	Bet Hero website	BetBurger website

The legal ceiling: your state

In the US, online sportsbooks are licensed state by state. Massachusetts lists seven licensed mobile sports wagering operators: BetMGM, Caesars Sportsbook, Fanatics, Penn Sports Interactive, Bally Bet, DraftKings and FanDuel.^[5] However many books a scanner covers, a bettor in Massachusetts can legally use at most those seven online. Each state sets its own list.

So the first filter is simple, and in a state with seven licensed operators it removes most of a headline count in the hundreds: of the books the scanner covers, which are licensed where you are?

Why scanner book counts are so high

International books. A tool built for a global audience can count bookmakers that aren't licensed in your state, or anywhere in the US. Those books may still feed the scanner's prices, but you can't bet there.

Books that price alike. Every book counts once in the total, whether or not its prices tend to match another book's. For finding a price difference, two books that usually post the same number are worth little more than one. A trial is the easiest way to see which of your books actually disagree.

Exchanges and other venues. Some counts include betting exchanges or prediction markets alongside sportsbooks. Those can be useful price sources, but they work differently and aren't available everywhere. See prediction markets vs sportsbooks.

Partial coverage. A book can be "covered" for main game lines and nothing else. If you bet player props or live markets, a book with no prop coverage doesn't help you, whatever the headline says.

Breadth is not depth

Two scanners with the same book count can be very different products. What matters for a given book is:

• Which markets are covered: moneylines, spreads and totals only, or props, alternates and live markets too.
• How often its prices refresh. A book refreshed every few minutes is far less useful for arbitrage than one refreshed every few seconds.
• How accurately its markets are matched. Books settle similar-looking bets differently. A soccer moneyline, for example, is usually a three-way market where a draw loses a bet on either team, while "draw no bet" refunds it.^[6] A scanner that confuses the two shows opportunities that aren't real.

Why usable books matter so much for arbitrage

Arbitrage needs two or more books disagreeing on the same market at the same time, and you need accounts at both. With seven legal options, there are only 21 possible pairs of books, and that's before accounting for books you don't hold or that price a market the same way. Sportsbooks also restrict accounts they see as consistently winning, which shrinks your usable list over time; see why sportsbooks limit winning bettors. A scanner that's excellent across 600 global books can still find little for a bettor with five open US accounts.

+EV betting is more forgiving, because you only need one book with a mispriced line. The fair price can come from a sharp book you never bet at.

How to check a scanner's real coverage

1. Get the list, not the number. A vendor should publish which books it covers. If it won't, treat the count as marketing.
2. Filter to your state. Cross the list against your state regulator's licensee list and the books you hold accounts with.
3. Check your markets. For each of your books, confirm coverage of the markets you actually bet.
4. Watch it during a trial. Note which of your books produce alerts. A book that never shows up in alerts may be listed but barely covered.
5. Ask about refresh. Ask how often each of your books updates, for pre-match and live.

Our testing methodology reports coverage the same way: books usable in the state we tested from, by market, with the vendor's claimed total shown separately and labeled "Vendor-reported."

The short version

A big book count tells you how much data the scanner collects. The number that decides whether it's worth paying for is how many of those books you can legally use, have accounts at, and bet the markets you care about. In a state like Massachusetts that number can't be higher than seven, and it's the one to ask about.