A reserve greyhound is a dog named with a race's field that runs only if a drawn dog is scratched by the appointed scratching time, and it then starts from that dog's box. Each controlling body sets that deadline.
Under the Greyhounds Australasia Rules (GAR), effective 1 January 2026, a race can carry one or two reserves, under the same conditions and penalties as the field (rule 85(8)). Thoroughbred racing's version is the emergency runner, and greyhound racing betting covers reserves alongside vacant boxes and no races.
When a reserve gets a start
| Before the deadline | Who runs | Rule |
|---|---|---|
| One dog scratched, two reserves | One, by ballot unless the controlling body decides otherwise | GAR 85(10) |
| The same at an NSW TAB meeting | The first reserve | NSW local rule 85A |
| Two dogs scratched, two reserves | Both reserves | GAR 85(6) |
| Any scratching after the deadline | No one: the box stays empty | GAR 85(6) |
In a final, reserves come in qualifying order (rule 85(11)). Greyhound Racing Victoria's Bottom-Up meetings and Racing Queensland's preferential box draw races draw no reserves, so a scratching there leaves a vacant box. If a race is postponed to another day, reserves scratched only because no vacancy arose are reinstated (rules 111(9) and 111(10)).
Which box a reserve takes
A reserve keeps its own rug, 9 (green and white stripes) or 10 (red, white and blue), but starts from the box drawn for the dog it replaces, and no other box changes (rules 85(5) and 85(6)). When more than one dog is scratched, a ballot decides a reserve's box unless the controlling body rules otherwise (rule 85(12)); at NSW TAB meetings it is held straight after the deadline (local rule 85A). Greyhound Racing NSW's results then mark a reserve with the box it ran from, such as from box 5 (checked 8 October 2026).
So a reserve's box can be unknown until scratchings close, which changes its price.
Example: Illustrative chances and price, not a real race. Dogs in boxes 2 and 7 are scratched, both reserves come in, and a ballot gives out the two boxes. You rate reserve 9, a railer, at 18% from box 2 and 7% from box 7. Before the ballot its chance is 0.5 x 18% + 0.5 x 7% = 12.5%, a fair price of 1 / 0.125 = $8.00.
| Where reserve 9 starts | Your chance | Expected value per $1 at $9.00 |
|---|---|---|
| Not yet known | 12.5% | 0.125 x 9.00 - 1 = 0.125, an average gain of 12.5 cents |
| Box 2 | 18% | 0.18 x 9.00 - 1 = 0.62, an average gain of 62 cents |
| Box 7 | 7% | 0.07 x 9.00 - 1 = -0.37, an average loss of 37 cents |
A $9.00 price taken before scratchings close is a bet on the ballot as well as the dog.
Risk: Betting involves risk. Expected value is an average over many bets, your chances are only estimates, and a +EV bet can still lose, and often does. See responsible gambling for limits and support.
How bets on a reserve are treated
- Tote: the tote rules gazetted in WA in 2010 treat any withdrawal before the start as a scratching. A bet on a reserve that does not start is refunded (rule 9.1), or in a double, quaddie or BIG6 moved to a substitute (rule 9.2(a)).
- All in: an all-in bet loses if the dog does not start; NSW on-course bets struck before the box draw are all in where the ticket says so (local rule 184S).
- Fixed odds: your bookmaker's terms decide, so check them before you back a reserve.
A bet on the scratched dog does not follow the reserve into its box: under the scratching rules it is refunded, or in a tote double, quaddie or BIG6 moved to a substitute, unless it was all in. Greyhound betting rules covers the rest of settlement, and greyhound place betting shows how a reserve that keeps the field at eight keeps three places paid.
Where B337 fits
B337 does not rate dogs: the chances above are yours. The Terminal shows each bookmaker's prices in its own column, the best available price picked out, beside exchange back and lay. Prices come from 40+ bookmakers across racing and sports, not all on every race, read on a repeating cycle: check one in your account 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. A reserve can miss out, start from a box that suits it badly, or lose from a good one. See responsible gambling for limits and support.