You can't breed will and heart they got it or they don't. Being damn good with a little luck don't hurt luck it determination dedication and opportunity meeting together
I agree JP...can't breed will and heart in but we can select for it...this is how I see traits that are not that easily seen at a first glance...
traits that are not readily seen in my minds eye are like the ones we can see...for instance/example...a red dog...if red were a trait for will and heart and a light cream red being the least amount and dark Irish red being a dog with so much will and heart that he could over heat and die from not quitting as long as there are hogs to be caught...if it were that easy everyone would have a medium to darker shade of red in their dogs...
I see hunting traits in the same way...