Vig / Juice

The first edge you ever have to beat isn't the other bettors or the bookmaker's models. It's the vig, quietly baked into every price you see.

Vig (or juice) is the margin the book adds so the odds add up to more than 100% implied probability. A fair coin flip is 2.00 each side; a book might offer 1.91 each way. That gap is their cut, win or lose.

It sounds small until you realise you pay it on every single bet. Beating a market doesn't just mean being right more than half the time, it means being right often enough to clear the vig first. Shopping for the lowest-margin books is one of the easiest edges going.