Originally Posted by jjaded
I have seen this video, but isn't the sharpie mark on the wrong place, shouldn't it be at the grommet not where the string is clamped on the tensioner. Correct me if I am mistaken, but as shown it seems the machine would not pull the second pull as far, not necessarily pull anymore string from the racquet. If one marked at the grommet and that mark was further away from the racquet after the second pull I would agree that that amount of string would have been "loose" in the racquet otherwise.
It does not matter where you put the sharpie mark. If the mark were placed at the grommet you would still see it farther from the racket just not as far. The reason the mark moved a greater distance is because that little portion of string from the racket to the tensioner is fresh string that has never been stretched. That small portion of string in the racket was the section of string between the racket and the tensioned on the last pull. If YULitle has marked the point on the tension head where the back of the gripper stopped after tension was pulled and he had not pulled the string out of the gripper and reset it the gripper would have ended up in the same place. All he showed was the first pull. Had he made a second pull with the string reset in the gripper it would have been pelled about an inch less or the distance he moved the string up in the gripper. It is just a parlor trick but i dont think he knew he was actually tricking you. I think he fell for it also.
Think about it for just a minute. You are pulling with a constant pull machine, and it goes back to some point. If you release tension and keep the string at the same place in the gripper and pull the same tension it will pull again to the same point.