I used to breed hounds and sold hundreds of pups and trained dogs all around the country. Breeding and training hounds helped raise my family, my son is still breeding hounds. In my experience, on the average, shy pups do not turn out as well as often as the more adventuresome pups, however I have seen shy pups turn out to be very good dogs. With that said, I like to go for the best odds, look for the most adventuresome pup and the pup that shows the least fear of anything, that's the pup I'd put my money on.
As bare.hunter said, only get pups out of top notch parents. There are good dogs in all the breeds but I had the best reproduction percentages for making big game hounds by breeding house-bred walkers, a higher percentage of the pups made top big game hounds than any other breed or breeding within a breed that I have seen. But, there are good dogs in every breed and even cross breeding can produce good hunting dogs, but, there are more variables when you crossbreed, less chance of knowing what the outcome will be. Some of my best dogs have been crossbred, but I rarely tried to breed them because it was too much of a guess as to how they would reproduce. Pups from crossbreedings often were not as good as the parents were. Regardless of breeding, if you are getting a pup from a proven cross where 75% or more of previous pups turned out good, then your odds are good of getting a great pup. If there was more than 1 or 2 culls in a litter that did not make good dogs, I would never breed those dogs again
When I was raising litters I noticed that as soon as they could walk you could usually spot the best pups by their adventurism. As the pups grew older it was usually the same pups that continued to be the most outgoing and they usually turned out to be some of the best dogs. At 4 weeks I usually had my favorite pup figured out and it rarely changed as they grew older.
When you look at the pups ask the owner which are the most adventuresome and then watch them closely to pick out yours. When you have bought your pup then it's your responsibility to make the pup what he can be. You will only get as much out of the dog as you put into him. He must have lots of opportunity to learn and hunt or you can't expect him to be as good as he should be.
Sorry for the long winded post.
