This scratching deductions calculator works out what a winning fixed-odds bet in horse racing returns after a late scratching, from your stake, the price, the declared deduction and your bookmaker's method.
The deduction is typed in, never worked out: scratching deductions covers where the figure comes from.
What to type in
- The bet: Win, Place or Each way.
- How the deduction is taken: Face value or Winnings only. Nothing is preselected, so there is no result until you pick.
- Stake: what you had on, or the amount on each half each way.
- Win odds and Win deduction (cents): the price you took, and the win figure declared, in cents, so 20 for 20c.
- Place odds and Place deduction (cents): the same for the place half, declared separately and able to differ by placegetter.
- Least a winning bet can be paid: the stake, the stake and 20% of face value, or none.
The formulas, and a worked bet
In the formulas, 20 cents in the dollar is 0.20; in the calculator, type 20.
- face value: return = stake x odds x (1 - deduction)
- winnings only: return = stake + stake x (odds - 1) x (1 - deduction)
Racing NSW's Rules of Betting take the cents off the ticket's face value (BR 14(4)), with BR 1 counting the stake inside that face value. They cover bets struck on NSW racecourses and in approved betting auditoriums and premises (BR 14(1)); WA's r 56 does the same for WA bookmakers. Online bookmakers set their own method in their terms, and some may cut only the winnings. Read yours, or try both on a settled bet: the Return matching your payout names the method.
An illustrative $20 at $4.50 with a 12c win deduction, floored at the stake:
| Face value | Winnings only | |
|---|---|---|
| Working | $20 x 4.50 x 0.88 | $20 + $20 x 3.50 x 0.88 |
| Return | $79.20 | $81.60 |
| Profit | $59.20 | $61.60 |
| Price it works out to | $3.96 | $4.08 |
Subtract one from the other and stake x deduction is left: before any floor, winnings only pays that much more, $20 x 0.12 = $2.40 here, or $12 on a $100 bet.
Deductions on place and each way bets
Each half takes its own figure. An illustrative $20 each way at $7.50 and $2.40, with an 11c win and 5c place deduction, on face value:
| Leg | No deduction | After deduction |
|---|---|---|
| Win, 11c | $150.00 | $150 x 0.89 = $133.50 |
| Place, 5c | $48.00 | $48 x 0.95 = $45.60 |
| Both, on $40 | $198.00 | $179.10 |
Both halves pay only if the runner wins; if it places without winning, the place half alone is returned, $45.60 where its placing's figure is also 5c. On winnings only they pay $20 + $130 x 0.89 = $135.70 and $20 + $28 x 0.95 = $46.60, $182.30 in all.
Deductions on a multi leg
Run the deducted leg through with the floor set to None, then type its last-column price into the multi bet calculator beside the other legs. On an illustrative $30 multi of $4.00 and $1.90 with 15c off the first leg, face value makes that leg 4.00 x 0.85 = $3.40, so the multi returns $30 x 3.40 x 1.90 = $193.80 against $228.00 undeducted; on winnings only the leg is 3.00 x 0.85 + 1 = $3.55 and it returns $202.35.
WA's Rules of Wagering cut the relevant leg and recalculate the multi price (Schedule 1, item 3A). On face value that matches cutting the whole ticket, as NSW BR 21(1) does for doubles; on winnings only it does not, since cutting the ticket pays $30 + $198 x 0.85 = $198.30. So your bookmaker's multi terms decide; where the NSW and WA rule books set a floor, it protects the whole ticket, not one leg. A leg whose own runner is scratched settles under those terms too. On the tote, a scratched quaddie, running double, daily double or Big 6 pick moves to a substitute, as exotic scratching rules sets out.
The floor under a deducted payout
The floor option applies the rule books' minimum. For the bets BR 14 covers, Racing NSW's BR 14(8) keeps a deducted payout at or above the stake, dead heats aside. WA's r 56(5) holds a WA bookmaker's payout at or above both the stake and 20% of face value, while RWWA's own fixed odds settle under r 62Q on the Schedule 1 scale with neither floor. Illustrative bets, on face value:
| Bet | Deduction | Arithmetic | At least the stake | Stake and 20% of face value |
|---|---|---|---|---|
| $40 at $1.25 | 25c | $50 x 0.75 = $37.50 | $40.00 | $40.00 |
| $16 at $7.50 | 84c | $120 x 0.16 = $19.20 | $19.20 | $24.00 |
The 20% floor binds only above $5.00, where a fifth of face value beats the stake, and once deductions total over 80c. A dead heat removes the NSW stake floor, a case the bet calculator works through.
Rounding, and what the calculator refuses
Figures are worked at full precision and rounded once, to the cent, so two can sit a cent from the exact gap. An illustrative $12.50 at $3.33 with 17c is $12.50 x 3.33 x 0.83 = $34.54875 on face value and $12.50 + $12.50 x 2.33 x 0.83 = $36.67375 on winnings only, shown as $34.55 and $36.67, $2.12 apart where the true gap is $2.125.
It refuses rather than guesses: a stake outside $0.01 to $1,000,000, a price outside $1.01 to $10,001, a deduction outside 0 to 100 cents, and a decimal comma, since "2,50" means $2.50 where a comma marks decimals and dropping it would read $250. A 0c deduction is real, not an empty box.
Reading a deducted price against the market
The last column is the price your bet is really on, to compare with the market. The Terminal shows prices from 40+ bookmakers across racing and sports beside Betfair back and lay, with each runner's price history, so a scratching's move sits next to the price on offer. Prices are read on a repeating cycle and can trail the bookmaker's own. Bookmaker names are trade marks of their owners. B337 is not affiliated with them.
Risk: Betting involves risk. A deduction can cut a winning bet to its stake, or below it where no floor applies, and a dead heat can cut it further; there is no guarantee of profit. See responsible gambling for limits and support.