What has to be addressed is how the "bad black belt got there in the First place", Nerves do play a large role in tournaments and students excel at different things. In our club our patterns are not tournament winning, however in Sparring our club always does well. A Black belt should represent the hard training and work that it took to achieve the belt. Everyone has different skills in the martial arts and it is hard to say that the reason for a black belt to look weak at sparing or in patterns is focus and determination. Maybe the black belt had an excellent showing in weapons or breaking events (hard to say, I wasn't there). It all starts in the intensity of training too...