RTP (Return to Player)
Definition
RTP 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.
Formula
RTP = 1 / Overround x 100% (or 100% - Margin)Example
If the overround is 104%, the RTP is approximately 100 / 104 = 96.2%. For every $100 wagered across the market, roughly $96.20 is returned as winnings.
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.
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.
Line Shopping
MarketLine shopping is the practice of comparing odds across multiple bookmakers before placing a bet to ensure you get the best available price. Even small differences in odds compound into significantly higher long-term profits.
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