The difference between your estimated true probability and the implied probability of the odds. Positive edge means +EV.
Your edge is the gap between what you believe the true probability is and what the market implies. If you estimate 55% and the odds imply 50%, your edge is 5 percentage points.
Edge can come from: better models, faster information (being first to react), exploiting stale lines, or identifying bookmaker errors. In prediction markets, edge often comes from domain expertise that the market hasn't fully priced in.
Having an edge isn't enough — you need to size your bets correctly (Kelly Criterion) and have enough volume for the edge to manifest through variance.
edge = trueProb - impliedProb EV% ≈ edge × (decimalOdds - 1) / impliedProb
The average profit or loss per bet if you made the same wager thousands of times. Positive EV means long-term profit.
Closing Line Value (CLV)Getting better odds than the final line at market close — the strongest indicator of long-term betting skill.
Sharp BettorA professional or skilled bettor whose action moves lines. Sharps consistently beat closing lines.