Learn
How an edge is actually made.
The same game gets priced twice. Learn to read the gap between them, in three ideas and about two minutes.
The core idea
Two venues price the same game. They rarely agree.
A sportsbook sets a line with a margin built in. Kalshi is a live order book where traders set the price directly. Different crowds, different speeds, different math. So a gap opens between them.
Strip the margin out of the book, and you can measure that gap exactly. That number is your edge.
Worked example · Bills to win
The method
Three steps, every market
Devig the books
Remove the sportsbook's margin so the odds sum to a true 100 percent. The median across books becomes the fair line.
Price the contract
A Kalshi contract pays a dollar on a win, so its price is a probability in cents. Both venues now speak the same language.
Measure the gap
Fair line minus contract price is the edge. Rank every market by it, and the biggest disagreements rise to the top.
Reference
The words you'll see
- The vig
- The margin a sportsbook builds into its odds. Both sides add up past 100 percent, and the excess is the house's cut.
- The fair line
- The median devigged probability across every major book. The consensus price, before anyone's margin.
- Edge
- Fair line minus the Kalshi contract price, in cents. Positive means the contract is cheap relative to consensus.
- Crossed market
- When two venues disagree enough that opposite positions at each lock in a profit no matter the outcome. Rare, and the strongest signal on the board.
- Closing line value
- Whether the price moved toward your entry by game time. Beating the close is the sharpest proof an edge was real.
Now watch it happen live.
Every concept here is running on the board right now, across five sports, refreshed every minute.
Open the screener