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Betting calculators
Rule 4 calculator: see what a withdrawn horse does to a winning bet
Enter your stake and price, the price of the horse that came out, and the result. The calculator looks up the deduction, takes it off the winnings, and shows the return with and without it, win only or each way, with Best Odds Guaranteed if it applies. Jump to the scale, or watch the explainer.
- Deduction applied
- 35p in the £
- Price paid at
- 6
- Total stake
- £10.00
- Total return
- £42.50
- Profit or loss
- £32.50
| Case | Return | Profit or loss |
|---|---|---|
| Price taken, no deduction | £60.00 | £50.00 |
| With the deduction | £42.50 | £32.50 |
What a Rule 4 calculator does
Rule 4 is a deduction from winnings that bookmakers apply when a horse is withdrawn from a race after your bet has been placed, once the final declarations have been made and before the race starts. The runner that is gone was part of the market, so the prices of the others were set with it in. The deduction takes that into account. It is taken from your winnings, never from your stake, and the stake is returned in full.
The calculator works out the deduction from the price of the withdrawn horse, takes it off the winnings of your bet, and shows the return with and without it. Enter the stake, the price you took, the price of the horse that came out, and the result. Switch the bet to each way and it takes the deduction off both parts. Tick Best Odds Guaranteed and it pays the better of your price and the starting price, then applies the deduction.
How to use the calculator step by step
Start with the stake on one part of the bet, the price you took and the result. If the bet is each way, switch Bet as to Each way and choose the place terms from the racecard. Next enter the price of the withdrawn horse as a fraction like 7/4, as evens or as a decimal. The deduction appears on the right as soon as you type.
If a second horse came out, enter its price in the optional box and the calculator adds the two and applies the cap. If your bookmaker gives a different deduction, switch Deduction to Enter my own and type it in pence. To see the effect of Best Odds Guaranteed, tick the box and enter the starting price. The table under the figures then shows four lines: your price with and without the deduction, and the best price with and without it. Set the result to Lost or Placed to see the other outcomes.
The Rule 4 scale
The deduction depends on how short the withdrawn horse was. The shorter its price, the bigger its share of the market and the bigger the deduction, from 90p in the pound for a horse at 1/9 or shorter to 5p for one at 10/1 or longer. The table shows the scale the calculator uses, taken from the published bet calculator and guide of Racing Post.
| Withdrawn horse’s price | Deduction | Withdrawn horse’s price | Deduction |
|---|---|---|---|
| 1/9 or shorter | 90p | 6/5 | 45p |
| 2/11 | 85p | 6/4 | 40p |
| 1/4 | 80p | 7/4 | 35p |
| 3/10 | 75p | 9/4 | 30p |
| 2/5 | 70p | 3/1 | 25p |
| 8/15 | 65p | 4/1 | 20p |
| 8/13 | 60p | 11/2 | 15p |
| 4/5 | 55p | 9/1 | 10p |
| 20/21 | 50p | 10/1 or longer | 5p |
Bookmakers publish their own tables and the edges of the bands can differ by a price or so. The scale here is a guide and not an authority. If your bookmaker’s terms give a different figure, choose Enter my own in the calculator and type the deduction from its table.
The differences are usually small, but they are real. One bookmaker may put 6/4 in the 40p band and another in the 45p band. A margin of a few pence in the pound changes the return by a few pence per pound of winnings. For a large stake or a long price, it is worth reading the bookmaker’s table instead of the guide.
How the deduction is applied
Suppose you back a horse at 5/1 with £10 to win and the 7/4 favourite is withdrawn. The scale gives 35p in the pound. Your winnings at 5/1 would have been £50. Take 35p in every pound off them and the winnings are £32.50, so the return is £42.50 including the stake. The stake is not touched.
| Case | Return | Profit |
|---|---|---|
| No deduction | £60.00 | £50.00 |
| With the deduction | £42.50 | £32.50 |
Read the table across: the bet wins either way, and the deduction cuts the profit by 35 per cent. Had the horse that was withdrawn been at 10/1, the deduction would have been 5p and the profit £47.50. A late withdrawal of a short-priced favourite costs far more than one of an outsider. Our Rule 4 explainer walks through the same example step by step.
What a withdrawal costs at different prices
The same winning bet can lose very different amounts depending on which horse comes out. Take £10 to win at 8/1, which would return £90 with no deduction.
| Withdrawn horse | Deduction | Return | Profit |
|---|---|---|---|
| 1/4 | 80p | £26.00 | £16.00 |
| 4/6 | 55p | £46.00 | £36.00 |
| 2/1 | 30p | £66.00 | £56.00 |
| 4/1 | 20p | £74.00 | £64.00 |
| 8/1 | 10p | £82.00 | £72.00 |
| 20/1 | 5p | £86.00 | £76.00 |
The pattern is steady. A 1/4 favourite taken out cuts the winnings by 80 per cent, a 2/1 horse by 30 per cent, and a 20/1 outsider by 5. This is why a withdrawal on the morning of a big handicap barely changes most bets, while the loss of the market leader in a small field changes all of them. Before a big race, look at the card for the prices of the horses at the head of the market.
Rule 4 on each way bets
An each way bet has a win part and a place part, and the deduction reduces the winnings of both. The place part’s winnings are already a fraction of the odds, and the deduction takes its share off that smaller figure.
| Case | Win part | Place part | Total return | Profit |
|---|---|---|---|---|
| Wins, no deduction | £50.00 | £20.00 | £70.00 | £50.00 |
| Wins, with the deduction | £42.00 | £18.00 | £60.00 | £40.00 |
| Places only, no deduction | £0.00 | £20.00 | £20.00 | £0.00 |
| Places only, with the deduction | £0.00 | £18.00 | £18.00 | -£2.00 |
With £10 each way at 4/1, place at a quarter of the odds, and a 20p deduction, a winner returns £42 on the win part and £18 on the place part, £60 in all, against £70 without the deduction. A horse that only places returns £18 instead of £20. The each way calculator lets you set a deduction on each selection in a multiple.
Two or more withdrawals
When more than one horse is withdrawn, the deductions are added together, and the total is capped. Most published rules cap it at 90p in the pound, so a bet on a winner always keeps at least 10p of each pound of winnings. The second box in the calculator takes the price of a second withdrawn horse and applies the cap.
| Withdrawn | Deductions | Applied |
|---|---|---|
| 7/4 and 10/1 | 35p + 5p | 40p |
| 4/1 and 7/2 | 20p + 20p | 40p |
| 1/4 and 2/5 | 80p + 70p | 90p (capped) |
A favourite at 7/4 and an outsider at 10/1 withdrawn together cost 40p in the pound. Two short-priced horses at 1/4 and 2/5 would add up to 150p, and the cap holds the deduction at 90p. Some bookmakers’ own rules give a slightly higher cap, so check yours.
Best Odds Guaranteed and Rule 4
Best Odds Guaranteed pays you the better of the price you took and the starting price. If a Rule 4 deduction applies as well, the order matters. BoyleSports states in its terms that it pays at the bigger odds after the Rule 4 deduction has been applied, and the calculator follows that order: it takes the better price first and then takes the deduction off the winnings. Other bookmakers set out the combination in their own terms and the effect on a given bet can differ.
| Case | Return | Profit |
|---|---|---|
| Price taken, no deduction | £70.00 | £60.00 |
| Price taken, with the deduction | £58.00 | £48.00 |
| Best Odds Guaranteed, no deduction | £100.00 | £90.00 |
| Best Odds Guaranteed, with the deduction | £82.00 | £72.00 |
With a price of 6/1 taken, a starting price of 9/1 and a 20p deduction, the winnings at the better price are £90 before the deduction and £72 after, so the return on £10 is £82. Without the guarantee the winnings would be £60 before and £48 after, a return of £58. The guarantee adds £24 to the return in this example, and the deduction takes £18 off the winnings that the guarantee paid. Read the operator’s own terms on the combination before you rely on it. Our Best Odds Guaranteed explainer shows how the guarantee pays on its own, and the horse racing betting sites guide lists the start time and conditions of each of the ten bookmakers.
When Rule 4 applies and when it does not
It applies to a horse withdrawn after you have bet and after the final declarations. A bet placed after the withdrawal is made at prices that already allow for the missing runner, so no deduction applies. If your own horse is the non-runner, the bet is void and the stake is returned. A bet that loses is not affected: there are no winnings to take a deduction from.
It applies to bets taken at a fixed price, such as an early or board price. BetVictor’s racing rules describe it as a deduction on a bet where you have taken a fixed odds price. A bet at the starting price is settled at the SP, which is set after the withdrawal and already allows for the missing runner, so there is nothing left to deduct. Terms for each bookmaker differ in the detail, so read the one that applies to the bet.
Bookmakers apply the deduction to win bets and to each way and place bets, and to the leg of a multiple that contains the affected race. How a deduction on one leg of an accumulator carries through to the rest is set out in the bookmaker’s terms, and the calculator treats a single bet.
Common mistakes with Rule 4
The first is taking the deduction from the stake. It comes off the winnings only. The second is forgetting the place part of an each way bet, which is reduced as well. The third is using the price of your own horse to look up the scale, when the scale uses the price of the horse that was withdrawn. The fourth is adding deductions without the cap. The fifth is trusting an old table: bookmakers revise theirs, and the terms on the day of the race are the ones that count.
Betting responsibly when a horse is withdrawn
A withdrawal changes a bet after you have placed it, and it is tempting to bet again to make up the difference. Do not chase. Decide a budget before the race, set a deposit limit in your account, and keep to it. Betting is for people aged 18 and over. GambleAware gives free and confidential help, and GamStop covers every licensed UK gambling site in one registration. How we compare betting sites describes the method behind the rest of the site.
How the calculator works
The deduction for a withdrawn horse is looked up on an eighteen-band scale by the horse’s price as odds against, and the deductions of several withdrawn horses are added and capped at 90p in the pound. The better price is chosen first when Best Odds Guaranteed is ticked. The winnings of a bet, the price minus one times the stake, are reduced by the deduction, the stake is returned in full, and each way bets reduce both parts, with the place part paid at the chosen fraction of the odds. Every deduction in the calculator and in the tables below comes from one scale in the code, and tests compare it with figures worked out by hand. The scale is a published guide; bookmakers publish their own tables and the terms of the bet decide how it is settled.
Questions about the Rule 4 calculator
What is Rule 4?
A deduction from winnings when a horse is withdrawn after you have bet and after the final declarations. It comes off the winnings, not the stake.
How much is the Rule 4 deduction?
It depends on the price of the withdrawn horse: 90p in the pound for 1/9 or shorter, down to 5p for 10/1 or longer. Each bookmaker publishes its own table.
Does Rule 4 apply to each way bets?
Yes. The deduction reduces the winnings of both the win part and the place part.
What if two horses are withdrawn?
The deductions are added together and capped, usually at 90p in the pound.
Is the stake affected by Rule 4?
No. The stake is returned in full on a winning bet. Only the winnings are reduced.
Does Rule 4 apply if my own horse is withdrawn?
No. The bet is void and the stake is returned.
Does Best Odds Guaranteed change the Rule 4 deduction?
It changes the price the deduction is applied to. Some bookmakers pay at the bigger price and then apply the deduction. Read your bookmaker’s terms.
Where does the scale in the calculator come from?
The published bet calculator and guide of Racing Post. Bookmakers publish their own tables, so the bands can differ slightly.
Does the calculator place a bet?
No. It works out returns from the numbers you type. It is not a forecast and the bookmaker’s terms decide how a real bet is settled.