Sportsbook margin
Sportsbook margin is the amount by which the implied probabilities across mutually exclusive outcomes exceed 100%, subject to the selected market and prices.
What it means
Two sides priced at -110 each imply about 52.38%, for a combined 104.76%. The amount above 100% is the market overround; removing it requires a stated no-vig method.
Taking the margin out gives the no-vig price, the market's own fair estimate. True Strength uses the no-vig chance in two places: to size a pick's stars from a blend of its own chance and the market's, and to measure closing line value against a fair close.
Limits and responsible use
A simple proportional no-vig calculation is one convention and may not represent how a sportsbook allocates margin.
Comparing prices can reduce cost but cannot make wagering safe or profitable. Keep stake limits independent of recent outcomes.