anybody thats done abit will know its not the rabbit its the land that makes the difference ,like running rabbits on wet sticky wheat will sapp the dogs alot quicker when on numbers,give the dog sore nails etc, fields with stone walls in them the rabbits got to turn off it with a dog up its arse it cant fly straight in like a field with thin hedges, sheep netted fields rabbits cant hit them flat out with a dog up its arse, , long tuffdy grass fields can be a help but can be a bas#### aswell when they keep running and then squatting, but where ever your dogs gotta be very FIT to take big number