I've read that. Use a mild bit for practice then to go a stronger bit for competition, that way they'll be more responsive. I don't compete but the same scenario works for Tuffy. I use a mild bit for as long as I can, til he starts lugging on it. Then I switched to a sweetwater shanked bit to get his respect back. Funny thing is, he never lugs on the sweetwater.
Now see I do it the other way around. I use an easier bit to compete for barrels anyway (what little I have competed), because I don't want to slow them down. You think I'm doing it backwards? I've never really asked about that.
Becky