My understanding in the first 4 mini-sets all reps should be a short negative, as quick a turn-around as possible into an explosive positive. If any reps in those first 4 sets should turn into a grinder, I should stop to preserve my Central Nervous system. In regards to the 5th set, the working set, I was wondering if the same rep performance is required and if a rep turns into a grinder, I should stop or it's okay to continue to work to just before failure. I hope that makes sense.