Odds & probability
Reading American, decimal and fractional prices, converting between them, and turning any of them into an implied probability.
Implied Probability: What the Odds Are Really Telling You
Implied probability is the break-even win rate hidden in every betting price. How to calculate it, strip out the vig, and test it against your own estimate.
How to Read Betting Odds: American, Decimal, Fractional
Learn how to read betting odds in American, decimal and fractional format, convert between all three, and turn any price into a probability and a payout.
Other topics
Market mechanics
Vig, hold, line movement, limits and the operational reasons a sportsbook prices the way it does.
Bet types
Spreads, totals, moneylines, parlays, teasers, props and futures — what each one costs you in expectation.
Bankroll & staking
Flat staking, percentage staking, Kelly, and the maths of variance, drawdown and risk of ruin.
Advanced concepts
Closing line value, steam, middling, arbitrage and the ideas that separate a priced bet from a hunch.