How betting markets work

Where a line comes from, why it moves, and what the closing number tells you.

  1. 1.
    How Do Sportsbooks Set Odds?

    A handful of market-making books and data suppliers build the first price; most retail books copy it, add a margin, and move it as bets and news arrive.

  2. 2.
    Why Do Betting Lines Move?

    Lines move when the book's view of the probability changes: team news, bets it respects, or a sharper book moving first. Balancing money matters less.

  3. 3.
    What Is the Difference Between Opening and Closing Lines?

    The opener is a book's first guess; the closer is the last price before the game. Beating the close is the best evidence of skill you can get.

  4. 4.
    What Is the Difference Between Sharp Money and Public Money?

    Sharp money is betting the book thinks knows more than its price; public money is everyone else. Published betting splits can't tell them apart.

  5. 5.
    What Is Reverse Line Movement?

    A line moving against the side most bets are on. It can hint that respected money disagrees with the crowd, but by then the better price is gone.

  6. 6.
    Why Do Some Bets Cost More Than Others?

    Every price includes the book's margin, and the margin varies by market: thinnest on main lines, wider on props and futures, and compounding on parlays.

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