Well, first of all, I think Thomas Crapper's opinion is full of (you guessed it) crap. After all, if gameness were not genetic, then why in the world are we being so selective in our breedings? In fact, why isn't gameness found as commonly in other breeds as it is in pit bulls, if genetics were not relevant? To suggest that gameness is mere "attitude" is ridiculous IMO. I have seen plenty of little mutts (and teenage punks) with "attitude," but if you slap the shit out of them, that attitude runs dry pretty quick
The cluelessness among dogmen with regard to gameness is incredible IMO. They act like gameness is either "there" or "not there," which is preposterous. The age old "game" or "cur" mentality (this is why I amended your heading, and some of your text, as it encouraged this mentality). It is precisely this total LACK of understanding that makes people label any dog that isn't 100% dead game a "cur" which has been a crime to the breed for decades.
The truth is, "gameness" (which is nothing but the will to win) comes in DEGREES in dogs, it isn't just "there 100%" in a dog or "not there at all" in a dog. It is the same with the ability to bite hard, the ability to breathe well, the ability to move well, etc. Likewise, these abilities are not "there 100%" or "not there at all" in a dog, they too come in varying DEGREES within different individuals. Our job as dogmen is to select dogs with high degrees of as many of these different attributes as possible, and to combine them in the right way. But to say, "I will never breed to a dog that doesn't have 100% gameness" is as stupid as saying, "I will not breed to a dog that doesn't have 100% hard mouth." There are plenty of truly great dogs that don't have 100% of either trait, but they have high enough percentages in ALL traits, and can direct and combine everything in the right way with their intelligence, in such a way as they will win consistently. (Take Robert T for example.)
The reason why the above dogs still produced well is because they had a FAIRLY-HIGH degree of gameness (as well as other good traits) compared to other dogs. They had enough good traits to compete at the highest level, and while they may have fallen short in some areas, they still were top-tier dogs. Trying to compare the saying "blood from a stone" to a dog that stopped at some point is retarded because stones have NO blood ... and to say a dog that competed in the fast lane has "no" gameness is (again) retarded. They had PLENTY of gameness (and other competitive attributes), they just did not have them as high (or combine them as well) as their opponent. Wondering "why" such dogs produced dogs better than themselves is like wondering "why" an average dog like Little Tater can produce an ace like Gr Ch Buck ... they can do it if you breed them the right way. Breeding "the right way" has to do with aligning the ancestors of a dog's pedigree correctly, so that you have the highest chance of bringing-out the best genes.
A dog with 70% gameness (down from a dog with 100% gameness) that is bred to another dog of 90% gameness (with the same 100% DG dog behind it) can have their genes aligned in such a way that more 100% DG dogs come out, because the chance of "pulling" the gameness genes out of that common ancestor are excellent. For example, I bred the DG Truman to Rio, and I bred Truman to Angel, and several pups out of both litters QUIT. I bred two of these pups together "before" they quit (they had looked okay in rolls), but after their parents quit I sold the pups out of them cheap. Well, guess what? Those pups all got ABUSED by people who "had to prove" their gameness ... and every last one of them took their deaths GAME. Why? Because they were double-grandpups out of a DG dog, that's why
Breeding to any dog that you kNOW where you're at with is, of course, to be standing on firmer ground. However, just because a dog is "untouched" doesn't mean he isn't an ace, you just don't know it yet
Jack