I used to do screening for game show contestants back in the 80s when shows like American Gladiators were first coming on the scene... and they had a rule that every contestant had to be able to do a minimum of 50 reps on pull ups. I said that wasn't possible... so the guy "showed me." He did 50 partial reps then finished strong and fast to show me how kick ass he was. Then I showed him a full extension rep... top to bottom... and he could get 6.