When the Bookmaker prices his book, he takes into account the chances of each horse winning relative to the chances of the other horses in the field based on all horses running the race.
However, sometimes horses are withdrawn for a number of reasons and often at the last minute when many bets have already been placed.
If the bookmaker was forced to pay out on the price of all bets placed up until that point you can probably see how this could be open to all forms of abuse so the Tattersalls Rule 4c Scale of Deductions was introduced to protect the bookmaker whilst still being fair to the punter (the alternative would be to just void all bets which wouldn't be much fun!)
Obviously, if it is the favourite which has been withdrawn, the picture alters significantly. If it is a rank outsider then some bookmakers take the view that it is not likely to affect the outcome of the race and so don't impose the 5p deduction found at the foot of the following table.
Please note: It has become apparent that some bookmakers are now making deductions of up to 90p in the pound for very short-priced favourites whilst some limit the deductions to 75p in the pound and this covers all horses priced 3/10 or lower.
Price of horse at time of withdrawal
Deduction from winnings:
1/9 or shorter 90p in £
2/11 to 2/17 85p in £
1/4 to 1/5 80p in £
3/10 to 2/7 75p in £
2/5 to 1/3 70p in £
8/15 to 4/9 65p in £
8/13 to 4/7 60p in £
4/5 to 4/6 55p in £
20/21 to 5/6 50p in £
If over 14/1 the liability would be unchanged. In the case of two or more horses being withdrawn before coming under Starters Orders, the total deductions shall not exceed 90p in £ (or 75p, depending on the bookie).
Example - £10 win bet, taking an early or board price of 9/1
2 horses withdrawn before the start.
One horse trading at 3/1 (deduction 25p)
Second horse trading at 14/1 (deduction 5p)
Making a total Rule 4 deduction of 30p in the £
£10 @ 9/1 = £90 WINNINGS on the bet.
Deduct £27 from the winnings part of the bet (90 x 30p)
The bet now wins £63 (SP 6.3 /1)
Then add on your original stake of £10
Total Returns would be £73 making a profit on the bet of £63
Some online bookmakers offer best odds guaranteed, meaning that if a punter takes an early price on a race and the Starting Price turns out to be better (that is, higher), then if the punter wins, the payout is at the Starting Price. This is aimed at removing hesitancy among punters prompted by fears of taking what might prove to be a poor (that is, low) price before the race.
Evens to 6/5 45p in £
5/4 to 6/4 40p in £
13/8 to 7/4 35p in £
15/8 to 9/4 30p in £
5/2 to 3/1 25p in £
10/3 to 4/1 20p in £
9/2 to 11/2 15p in £
6/1 to 9/1 10p in £
10/1 to 14/1 5p in £
If a horse comes under Starter's Orders but refuses to race, the bet will be a loser.
In all horse races where a runner is withdrawn, or adjudged not to have started - and therefore been declared a Non-Runner by the starter - stakes on that selection will be refunded. (The exception to this being Ante Post bets)
Article written by Michael Flynn.