So someone asked me:
Let's say theoretically if you cross to working hunting dogs, are all puppies likely to inherit that? Or is it an unsure percentage? And how much of it is pure instinct and how much would you say is how they're started/introduced to the hunt?
That's a difficult question to answer, since there are so many different types of prey, and different styles of hunting. I would say in my experience (primitive breeds, NK) whether or not your dog will hunt is almost 100 percent instinct (they are born with the necessary data).
The Nihon Ken is a complete, primitive hunter, like a wild canid. It goes through the entire hunting cycle: find, chase, stop/kill. Many dog breeds have been bred specifically to only do one part of the hunt sequence (ie bird dogs taught to find/point).
The complete hunting package for an NK requires it to have hunting drive, good nose, speed, etc etc and enough grit to stop/attack its prey. Every generation you create that is not bred to specifically maintain hunting functionality is mathematically decreasing the odds of producing a litter of working dogs.
So yes, a pup from two working parents has higher odds of hunting, but there's never a litter (from any breeding) that you can say will 'work' 100 percent. More than just two working parents, you need generations behind the parents of solid, tested, working dogs. If you have that, your odds get pretty good. I would say the percentage of dogs that will work boar, from a purpose bred line, will vary according to the skill/selection of the hunter breeding them. But to have 90 percent of pups produced turn out as even half decent hunters, well those are impressive numbers (and I respect any kennel turning out those pups).
There are very few purebred Nihon Ken (of any of the breeds) that have dedicated working kennels/lines. So, the percentages of purebred dogs that will work is not extremely high, but is better in some breeds over others. If you're hoping to hunt boar or dangerous game, the Kishu is still rather viable, while the Akita is most likely not going to work out. It's a numbers game.
I'm very much a proponent of Nature over Nurture. You can tone down what is in a dog through nurture/training, but you cannot put something in there that wasn't there to begin with.