Expected value calculator
Plug in the line you got from the book and your own estimated win probability. The calculator shows the expected value in dollars and as a percentage of your stake — the only test that matters for whether a bet is actually +EV.
EV in one line
EV = (win prob × profit if win) − (loss prob × stake). Or equivalently, EV% per unit = p × (decimal odds − 1) − (1 − p) where p is your true win probability. Positive EV means the bet pays more than its risk over the long run. Negative EV is a charity contribution to the book.
“Your edge vs book” is the difference between your probability and the book’s implied probability (1 ÷ decimal odds). Any positive edge is +EV; how much depends on the price.
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NotaSportsGuru publishes a daily slate of player props and match lines, each priced against the book and ranked by edge. Members see the full edge and confidence on every leg.