Line Movement
Definition
Line movement refers to changes in odds or point spreads between the time a line opens and when the event starts. Movements are driven by betting action, injury news, weather changes, or other new information. Tracking line movement helps identify where sharp money is flowing.
Example
A soccer match opens with the home team at 1.80. Over the next 24 hours, the price drops to 1.65, indicating significant money backing the home side. This movement may signal value on the other side or confirm sharp action.
Related Terms
Vig / Juice
MarketVig (short for vigorish) or juice is the commission the bookmaker charges on each bet. It is built into the odds so that the sum of implied probabilities exceeds 100%. The vig is how sportsbooks guarantee a profit regardless of the outcome.
Overround
MarketOverround (also called margin or book percentage) is the total implied probability across all outcomes in a market. The amount by which it exceeds 100% represents the bookmaker's built-in advantage. Lower overround means fairer odds for the bettor.
RTP (Return to Player)
MarketRTP is the inverse of the overround, expressed as the percentage of total stakes that is returned to bettors as winnings over time. Higher RTP means lower bookmaker margin and better value for bettors.
Steam Move
MarketA steam move is a sudden, sharp line movement caused by heavy action from professional bettors (sharps) across multiple bookmakers simultaneously. Steam moves signal strong opinions backed by significant money and can indicate genuine value before the broader market adjusts.
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