Factoring in the ability to breathe is a dog by dog basis. There are dogs that are nutters before anything happens. Geeked up is a good word for it as that's exactly what they are. They want to put you away quick as was mentioned. The downside to those dogs is that a lot of them put themselves in a position to quit due to expending so much energy early on. You have some dogs with certain styles that lends to the belief they have a great ability to breathe. That may be true, but you will find out if the animal ever has to adapt to a different style due to their opponent. And considering that could never happen, you would never actually know for certain if that was the case or not.

If a person is serious about competition, the ability for the dog to breathe is greater than any amount of mouth or ability. Without O2 your dog is through.