Betfair Starting Price (BSP): How Exchange Odds Work
The Betfair Starting Price (BSP) is the price at which all remaining back and lay bets on the Betfair exchange are matched at the moment a race starts, set by supply and demand between punters rather than by a bookmaker. Commission is charged on net winnings. Because it reflects pure market consensus at the jump, BSP is widely used as a benchmark price in betting analysis.
An exchange, not a bookmaker
Betfair is a betting exchange: punters bet against each other, backing (betting a horse wins) and laying (betting it doesn't), with the exchange matching the two sides and charging commission on net winnings. Prices are set by nothing but supply and demand.
The Betfair Starting Price is the reconciliation of all outstanding BSP-nominated backers' and layers' money at the moment the race jumps — a single market-clearing price, computed from real staked money rather than a bookmaker's opinion.
BSP versus fixed odds and the tote
Fixed-odds prices are offered by bookmakers, include their margin, and are locked when you bet. Tote (pari-mutuel) odds pool all bets and share the pool among winners, so your dividend isn't known until betting closes. BSP sits apart from both: no bookmaker margin is built into the price itself (the exchange earns via commission), and the price is determined at the jump.
Consequently BSP is often used by professionals as the honest yardstick of what a horse's true market price was — which makes it the standard reference price for measuring betting results and testing strategies, including in our own backtesting.
Practical realities
BSP has no guaranteed size: your bet is matched against whatever money is on the other side at the jump, and in thin markets the BSP on outsiders can swing wildly. Commission rates on winnings vary by market and account, so the price you see needs that haircut applied when comparing to fixed odds.
Australians should also note that exchange access and rules differ by state and product, and prices late in betting can move sharply as serious money arrives — the last minutes of an exchange market are their own ecosystem.
Common questions
Betting that the horse will NOT win. On an exchange you act as the other side of a backer's bet: you collect their stake if the horse loses, and pay out at the agreed odds if it wins.
Neither is universally better. A fixed price taken early can beat BSP if the horse firms; BSP wins when the horse drifts. Which is better on average depends on whether you can identify prices likely to shorten — the whole craft of value betting.
Because it's a single, objective, market-derived price available for every runner, free of any individual bookmaker's margin or limits — a fair common yardstick for testing strategies.
Guides teach the method. On race day, members see it applied: Kingsley's selections, ratings and maps on every card.
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