The Betfair Starting Price (BSP) is the single price the Betfair exchange sets for each runner when the market is suspended at the jump, and every bet matched at BSP gets that price. It is found by balancing the bets placed "at SP" on both sides, bringing in unmatched exchange bets where they improve the price for one side. The price is unknown until then, and commission comes off your net winnings afterwards: a winning $1 back at a $5.40 BSP returns 1 + 4.40 x 0.93 = $5.09 at an illustrative 7% rate.
You back at BSP with a stake and lay at BSP with a liability, the most you can lose. BSP is offered on racing markets, place markets included, and each market shows whether it carries one. The examples here use illustrative amounts; the exchange's own rules set the details, so check them before you rely on one. Lay betting explained covers the lay side from the start.
How BSP is calculated at the jump
Step by step, in plain terms:
- Before the jump, SP backers say how much they want to stake, and SP layers how much they are prepared to lose.
- When the market is suspended at the jump, the exchange looks for the price at which the backers' winnings equal the layers' liability: SP back stakes x (BSP - 1) = SP lay liability.
- Unmatched exchange bets still waiting on that runner are brought in wherever they improve the price for one side, even when the SP bets balance on their own. Waiting lay offers can lift the price for SP backers, and waiting back bets can lower it for SP layers.
- Everyone matched at SP gets the same price. From then on the bets are ordinary matched bets, settled with the rest of the market.
Example: a simplified illustration with made-up amounts, not the exchange's full method. At the jump, Runner 3 has $1,800 of SP back stakes, $5,400 of SP lay liability, and $500 of unmatched lay offers waiting at $4.40.
With the SP bets alone, the balancing price is 1 + 5,400 / 1,800 = $4.00, because $1,800 x (4.00 - 1) = $5,400. The waiting offers change that. At $4.40 the SP layers cover 5,400 / (4.40 - 1) = $1,588.24 of the backers' stakes, and the offers at $4.40 cover the other 1,800 - 1,588.24 = $211.76, so every SP backer is matched. Above $4.40 those offers drop out and the SP layers alone cannot cover $1,800, so in this simplified case BSP lands at $4.40.
The SP layers end up laying at $4.40, not the $4.00 their own money implied: the waiting offers worked in the backers' favour. The $288.24 of offers left over were not matched at SP, and their own settings decide what happens to them. The real calculation also handles price limits, minimum sizes and many orders at many prices.
Backing and laying at BSP, with price limits
A back at BSP names a stake. A lay at BSP names a liability, and the stake follows from the price: lay stake = liability / (BSP - 1). Either can carry a price limit, the lowest BSP a backer will take or the highest a layer will, and if BSP lands outside it that bet is not matched at SP.
Example: illustrative prices, with an illustrative 7% commission. You back Runner 5 at BSP for $40 with a $4.00 limit, and lay Runner 2 at BSP with an $88 liability and a $6.00 limit. Each row shows what happens if that runner's BSP lands at that price.
| BSP at the jump | Back $40, limit $4.00: winnings if it wins | Lay, $88 liability, limit $6.00: stake | Lay: kept if it loses, after 7% |
|---|---|---|---|
| $3.20 | Not matched, below the limit | 88 / 2.20 = $40.00 | 40.00 x 0.93 = $37.20 |
| $5.40 | 40 x 4.40 = $176.00, or $163.68 after 7% | 88 / 4.40 = $20.00 | $18.60 |
| $7.60 | 40 x 6.60 = $264.00, or $245.52 after 7% | Not matched, above the limit | Nothing |
The back risks its $40 whatever the price. The lay risks its $88 liability whatever the price, but what it wins shrinks as BSP lengthens: $37.20 at $3.20, $18.60 at $5.40. A BSP lay cannot lose more than the liability you set, yet at a long price it risks a lot to win a little, which is what the $6.00 limit prevents. Without one, a $21.00 BSP would lay just 88 / 20 = $4.40, keeping 4.40 x 0.93 = $4.09 if the runner loses, against the $88 at risk.
The exchange holds a BSP lay's full liability from your balance until the market settles. An ordinary exchange bet can also end up at BSP: with take SP chosen, whatever is unmatched at the jump joins the SP bets, and the take SP entry covers how a converted lay is sized.
Risk: Betting involves risk. A BSP bet goes on at a price you cannot know when you place it, a lay can cost its whole liability, and there is no guarantee of profit. See responsible gambling for limits and support.
Near and far prices before the jump
Before the jump the exchange shows two projections of BSP, each worked out as if the market were reconciled at that moment:
| Projection | What it counts | In the Runner 3 example |
|---|---|---|
| Far price | SP bets only, as if no exchange bets were waiting | $4.00 |
| Near price | SP bets plus the unmatched exchange bets waiting on that runner | $4.40 |
Both move as money arrives. If another $1,000 of SP lay liability came in before the jump, the far price would rise to 1 + 6,400 / 1,800 = $4.56. The SP layers alone could then cover every backer, the offers at $4.40 would drop out of the sum, and the near price would move to $4.56 as well.
- A gap between the two says waiting exchange bets are shaping the price. The near price uses the same inputs as BSP itself, so it is the closer guide.
- A projection is not a price. It can move a long way in the last minutes, most of all in a market with little money, where a few late SP bets change the balance.
- To choose between a fixed price now and BSP later, compare the fixed price with the near price after commission. A $4.40 near price is worth 1 + 3.40 x 0.93 = $4.16 to a winning backer at 7%, so a fixed $4.30 pays more if nothing changes.
Risk: Betting involves risk. The near price can move after you take a fixed price, so the comparison holds only for the money in the market at that moment, and there is no guarantee of profit. See responsible gambling for limits and support.
Taking a fixed price or waiting for BSP
A fixed price is known when the bet is struck, while BSP is known only at the jump and commission comes off its net winnings. So BSP pays more than a fixed price only if it lands above break-even BSP = 1 + (fixed price - 1) / (1 - commission rate). Against a fixed $6.00 at an illustrative 7%, that is 1 + 5.00 / 0.93 = $6.38. Before the jump, the near price is the closer guide to whether BSP will get there.
A tote dividend follows the tote rules: under the NT's rules, for example, dividends are paid from the bets less refunds less the operator's commission. Racing NSW says the official starting price at NSW TAB race meetings comes from the NSW Official Price, calculated from the prices of the larger wagering operators (checked October 2026). Starting price betting explains how bookmaker SP bets work.
BSP and the tote are both unknown when you bet, which makes them a natural pair, and BSP vs tote compares them with commission included.
BSP as the racing closing line
BSP is the market's final word before the race, set by money on both sides rather than by a bookmaker's margin, which is why it serves as racing's closing line. Closing line value (CLV) against it is your price / BSP - 1: with illustrative prices, $7.00 taken in the morning on a runner whose BSP is $6.10 is 7.00 / 6.10 - 1 = +14.8%. Averaged across many bets, a positive figure says your prices beat the market's final view. It is not a profit figure, and a bet that beats BSP still loses whenever the runner does. Closing line value in horse racing sets out the method and the records it needs.
Risk: Betting involves risk. Beating BSP is evidence about your prices, not a promise about results, and past results are no guarantee of future results. See responsible gambling for limits and support.
Scratchings, thin markets and other edge cases
- A late scratching. Under Racing NSW's Rules of Betting, the rule book for NSW on-course bookmakers, winning fixed-odds bets struck before a late scratching are paid less a cents-in-the-dollar deduction that the stewards declare; online bookmakers apply their own terms. The exchange adjusts matched bets under its own rules, through what it calls reduction factors, and the two need not match. Scratchings and deductions covers the bookmaker side.
- A thin market. With few SP bets and little money waiting, one late order can move BSP a long way from the prices shown a minute earlier; the liquidity on the runner says how much weight its BSP deserves.
- Place markets. Each exchange place market has its own BSP, so judge a place bet against the BSP of a place market paying the same number of places, never the win BSP.
- Minimum sizes. The exchange can set a minimum for SP bets and cancel a smaller one, a converted remainder included.
- No BSP. Not every market carries one, so check the market before you plan a BSP bet.
- Dead heats. A dead heat settles under the exchange's rules, which can differ from a bookmaker's or the tote's.
Mistakes with BSP bets, and what each costs
| Mistake | What it costs, with illustrative prices | The fix |
|---|---|---|
| Laying at BSP with no price limit | At a $21.00 BSP an $88 liability lays $4.40, keeping $4.09 after 7% if the runner loses | Set the highest price you will lay at |
| Reading the near price as BSP | A $4.40 near price became $4.56 when $1,000 of SP lay liability arrived | Treat both projections as estimates until the jump |
| Comparing a fixed price with BSP before commission | A $5.40 BSP is worth $5.09 to a winning backer at 7%, so a fixed $5.20 beats it | Compare after commission |
| Checking a place bet against the win BSP | Win and place markets have different prices and different BSPs | Use the matching place market's BSP |
| Expecting a fixed lay stake | An $88 BSP lay stakes $40.00 at $3.20 but $20.00 at $5.40 | Size BSP lays by the liability you can afford |
Where B337 fits
The Terminal shows racing and sports prices from 40+ bookmakers side by side with Betfair back and lay, price history and closing lines, the last prices before the jump. You can see where a fixed price stands against the exchange before you choose between taking it and waiting for BSP.
B337 places no back or lay bets on the exchange: a BSP bet, its price limit and a take SP setting are yours to choose in your own exchange account. Prices are read on a repeating cycle, not tick by tick, so check the exchange's own figures before you bet. A free account opens a limited view of the Terminal with live odds. Bookmaker names are trade marks of their owners. B337 is not affiliated with them.
Risk: Betting involves risk. BSP and its projections can move right up to the jump, a screen read on a cycle can trail them, and there is no guarantee of profit. See responsible gambling for limits and support.