If you don't have a good jump dog, then you won't bag many rabbits. A good jump dog will eagerly approach any brush pile or briar thicket looking for the prey. The trail dog meanwhile might sniff around the brush pile, or even enter it somewhat, but not with the zeal of the jump dog. When the rabbit's nerves will take it no longer, it will burst from the cover and flee. The trail dogs take over the hunt and pursue, the jump dogs follow.
Some people refer to the chase as a race.
I have seen the rabbit outsmart the dogs many times. The rabbit will sometimes backtrack about 50 feet, then jump about 5 feet to one side of the path it took. It hides there, motionless, as the dogs with their noses to the ground go by in single file. At the end of the trail, the dogs lose the scent and wander about looking for it again. The rabbit then takes off in the opposite direction free of the dogs' pursuit.