Most gyms have other setters agree on ratings. So it's not just Bob's opinion that matters, its multiple of the gyms setters opinions too. If Bob keeps setting

Most gyms have other setters agree on ratings. So it's not just Bob's opinion that matters, its multiple of the gyms setters opinions too. If Bob keeps setting problems that he says are v5 and are actually v3, the other setters will say so and the gym will take the groups agreed upon rating (at least thats how my gyms have done it). Sometimes the group can be wrong though, or the beta is super difficult and no one gets it so the climb feels grades above what was intended.