Teacher's Bet.

Learn the Math Behind Betting Markets

No black boxes and no paywall. Each guide explains one piece of the math behind a betting market and hands you the calculator that shows the full derivation on your own numbers. Start anywhere.

How a Sharp-Consensus Fair Line Is Built (and How to Build One Yourself)The method behind a de-vigged, sharp-anchored fair line: strip the vig from every book, pool the lines in log-odds around a line you trust, and read an honest confidence signal. Worked step by step on a known sharp line.How to De-Vig Odds: Find the Fair Probability Behind a LineDe-vigging removes the sportsbook's built-in margin so a posted line reveals its fair probability. Learn the proportional, power, and Shin methods, step by step, with a worked example.Expected Value (+EV) Betting: How to Calculate Your EdgeA +EV bet is one whose price beats its fair probability. Learn how to calculate expected value from a de-vigged sharp line, with a worked example and the free +EV scanner.Arbitrage Betting: How the Math Works (with Calculator)An arbitrage exists when the inverse decimal odds across books sum to less than one. Learn the condition, how to split stakes, the execution risks, and try the free arbitrage calculator.The Kelly Criterion: How Much to Stake (and Why Fractional)The Kelly criterion sizes a bet to maximize long-run growth. Learn the formula, why full Kelly is dangerous with a noisy edge, and try the free fractional Kelly calculator.Closing Line Value (CLV): The Metric That Actually Measures SkillClosing line value compares your price to the de-vigged closing line, the fastest-converging measure of betting skill. Learn why it beats win rate, and grade your bets free.