What makes a strike dog?

To me a strike dog is a dog you take where you think there may be hogs and turn it loose if there are any that have been through the area within an few hours they locate and bay. I like my dogs to hunt out in no sign at least 500 yards if they smell something they will roll with it till they catch up to the hog my dogs I don't feel can take a track that's older than 3-4 hours depending on conditions both my dogs I consider strike dogs because they are searching for pork when on the ground my brother has a couple that will hunt a little but they are always listening for my dogs to open then they head to them I call those bay dogs and they don't hold as much value to me if any. I don't walk much either unless its to a bay.