The Linemaker — Inside the Book
Illustrative simulation — not a live market. Books open a line that builds in vig, then re-shade it as money flows in. This is our bookmaker engine simulating a full day of action on an example LAD/SDP game — opening line, every wager, every move, final exposure — so you can see exactly how the book thinks. The pricing math is real; the matchup and order flow are a worked example.
Each step is the line response to incoming wagers. Sharp money (large bets) moves the line more than public money.
A perfectly balanced book wins the vig regardless of outcome. This book is slightly home-loaded — exposure is positive either way, but bigger if LAD wins.
| Step | Trigger | LAD Price | SDP Price | Imbalance | Handle A | Handle B |
|---|
Sportsbooks don't try to predict winners — they try to balance their book. The goal is to take roughly equal money on both sides at the vig'd price, so the house pockets the juice regardless of outcome. Every bet that arrives moves them away from that balance, so the line adjusts.
But balance isn't always achievable. Public bettors flock to favorites and over totals; books deliberately shade those lines (price them slightly worse for the popular side) to compensate. That's where sharps live — they take the unloved side at a price that's better than fair.
The kicker: when sharp money hits, the book doesn't fade it — they follow it. A steam move on one book triggers the entire market to adjust. That's why you see same-direction line moves across all six major books within 60 seconds.