Fair Odds Calculator

Models a hitter's next game from the ground up: estimates his per-plate-appearance outcome rates, starting from his season line (regressed toward the league) and nudged by his recent form and quality of contact. Optionally pick the opposing pitcher and ballpark to layer in the matchup and park factors. It then estimates his expected plate appearances and runs a 20,000-game Monte-Carlo simulation for each prop's probability and its fair (no-vig) odds. Type the book's American odds to see your edge, EV and Kelly stake. The Adjustments panel shows exactly which factors moved the price.

No RBI or stolen-base props: the play-by-play data has no base-runner state, so those can't be modelled honestly.