why did spitz get to the rabbit before the other dogs?

One night the dogs spot a rabbit, and they chase after it, joined by a nearby pack of fifty police dogs. Buck, leading the pack, rejoices in the hunt, all of his instincts overwhelming him. Spitz, cold and calculating, takes a different route to head off Buck before he can reach the rabbit. Spitz jumps upon the rabbit, and without thinking Buck leaps upon him. He knows that their time has come. This is a fight to the death.