Astonishing Judo, first contact tactics: A Biomechanical evaluation of   tactics at start of high level competitions
  This paper is focalized on the limit application of judo throws, by tactics at first contact time, with some astonishing information at a first seeing, but biomechanically grounded, not often applied or because against the sound common sense or out the old oral judo tradition. To do so we provide an appraisal of the grips concept and his consequences in the Olympic sport judo from a biomechanics perspective, we will try to deeper both the concept and the function of grips and define the potential application of some throws without grips. Broadening this situation we try to underline some specific throwing situation in which grips are or not at all applied or applied in non conventional way. We describe at first the problem from the theoretical point of view. And as second point we try to find practical application, original or already developed in high level competitions. The provocative words Judo without grips or throw without grips are connected to the limit application of some biomechanical tricks, grounded on two well known physical principles: the time advance in the attack, in Japanese Sen no Sen (already applied in real competitions), and the utilization of the own inertia connected to high attack speed to apply in totally original way one of the two biomechanical tools utilized to throw the human body. 
Attilio Sacripanti
physics.pop-ph