ROI (Return on Investment)

Closing Line Value measures the difference between the odds at which you placed a bet and the final odds when the market closes. Consistently beating the closing line is widely regarded as the single best predictor of long-term profitability because closing odds reflect the most efficient market price after all information has been incorporated.

Expected Value is the average amount you can expect to win or lose per bet if the same wager were repeated many times. A positive EV (+EV) bet is one where the bookmaker's odds imply a lower probability than your estimated true probability, giving you a mathematical edge.

Implied probability is the conversion of betting odds into a percentage that reflects how likely the bookmaker considers an outcome. It includes the bookmaker's margin (vig), so the sum of all implied probabilities in a market exceeds 100%.

True probability is the estimated real likelihood of an outcome occurring, stripped of any bookmaker margin. It is derived from sharp market lines or statistical models and serves as the benchmark against which you measure value.