Betting guides
Betting Maths Guides
Learn the key betting maths concepts behind odds, implied probability, overround, bookmaker margin, free bets, matched betting, each-way betting, Rule 4, extra places, hedging, dutching, arbitrage, cash out and back/lay betting.
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These core guides explain the most important concepts behind the calculators on Betting Maths.
What Is Implied Probability?
Learn how betting odds convert into percentage chance and why implied probability matters.
Core guideBookmaker Margin Explained
Understand bookmaker margin, overround, book percentage and how market prices are built.
Core guideWhat Is a Free Bet?
Learn how free bets work, why stake not returned matters, and how offer value is calculated.
All betting guides
Browse all current Betting Maths guides below.
What Is Implied Probability?
Convert odds into percentage chance and understand what a price is suggesting.
Bookmaker marginBookmaker Margin Explained
Learn how bookmaker margin, overround and book percentage are connected.
OverroundWhat Is Overround in Betting?
Understand how betting markets can add up to more than 100%.
BookmakersHow Bookmakers Make Money
Learn about overround, odds movement, liability management and weight of money.
RiskCan You Always Beat the Bookie?
Learn why guaranteed betting systems are risky and what maths can actually show.
Free betsWhat Is a Free Bet?
Understand free bet value, stake not returned, free bet lay stakes and offer terms.
Matched bettingWhat Is Matched Betting?
Learn how qualifying bets, free bets, back bets and lay bets work together.
Free bet termsStake Returned vs Stake Not Returned
Learn the difference between cash-style returns and stake-not-returned free bets.
Horse racingWhat Is Rule 4 in Horse Racing?
Learn why deductions happen after non-runners and how Rule 4 affects winnings.
Extra placesWhat Are Extra Places in Each-Way Betting?
Understand enhanced place offers and how they compare with standard each-way terms.
Each-wayEach-Way Betting Terms Explained
Learn win part, place part, place terms, extra places, non-runners and Rule 4.
HedgingHow to Hedge a Bet
Understand back and lay hedging, lay liability, commission and greening up.
Cash outHedging vs Cash Out
Compare bookmaker cash out offers with manual hedge calculations.
DutchingWhat Is Dutching in Betting?
Learn how dutching splits stakes across multiple selections.
ArbitrageDutching vs Arbitrage
Understand the difference between stake splitting and covering all outcomes.
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Guides by topic
Odds and probability
Bookmakers and margin
Free bets and offers
Horse racing and each-way
Staking methods
Hedging and exchanges
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