Actually, any "genetic potential" can be ruined at any point in life.
Also, I think your post reflects the common confusion between DEAD gameness and mere gameness.
Gameness is merely "the will to win."
DEAD gameness is "the will to win that exceeds the will to survive" (the maximum amount of gameness possible).
- Most bulldogs are fairly game when compared to other breeds;
- Some bulldogs are so game they will outlast most other bulldogs;
- A few bulldogs are so deeply game they will die before they stop.
The assumption of most people is that gameness = DEAD gameness, but this is untrue. Gameness is merely an adjective like the word "fast." The word "fast" may seem informative, but upon closer inspection needs more qualifying words to modify it, in order to make sense. (E.g., not-so-fast, fairly fast, extremely fast, the fastEST, etc.) Ultimately, the word "fast" by iteself means nothing. To drive home the point, the sentence, "He is fast," is relatively meaningless. Fast compared to what? Another fat man? A triathelete? A cheetah? What? Furthermore, not only is the word fast by itself relatively meaningless, but a man's speed can vary from day to day, based on circumstances, as well as throughout his lifetime. What if he breaks his leg? What if he's 77 years old? In the end, no runner is able to maintain his very best speed, all day everyday, throughout his lifetime. His "genetic speed" WILL vary at different points within his lifetime.
By the same token, the word "game" by itself means nothing. Game compared to a beagle? Game compared to a so-so bulldog? Game enough to scratch on a broken leg, that may hurt, but the dog is still fresh? Game enough to scratch after being behind for 2 hours in a state of shock, with half his blood supply gone, for the last :30? 100% dead game, died in holds??? How game are we talking about? The idea that a dog is either "dead game or a cur" is preposterous to anyone with a brain, because there are degrees of gameness. That is like saying a person is either as fast as lightning or is "slow"; it is preposterous because there are degrees of speed. Furthermore, even when speaking of the gamest of dogs, said dog was NOT "that game" his whole life. He may not have hit a lick till he was 3 years old ... and he may not be "that game" when he is 11 years, dying of lymphatic cancer, with his whole body falling apart either. His gameness too WILL vary throughout his lifetime ... and yet, despite this reality, the common dogman expects a bulldog to be able to maintain absolute 100% dead gameness from birth till death, or "he is a cur," which is ridiculous.
Thus, in the end, only simple-minded people say, "game or cur." Such people will never really understand the nuances that prove (once again) there will never be "one answer" to any complicated question. As usual, each case is unique, and therefore each set of circumstances must be looked at by a truly educated, knowledgeable dogman. Because, you bet, gameness CAN be modified by the circumstances of life ... including age, health, physical condition, style of opponent, experiences in school, parasite load, etc.
Jack