Having understood

the first two principles we must now examine the final result in the moment of cutting, called Ki-ken-tai-ichi, or the moment when 'spirit-sword-body' become 'one'. At the moment of impact there must be focus of all available forces to one point and this is best developed in three explanatory diagrams.

9a shows the angle of approach as the Shinai strikes. In this basic action the only available force is that implied by the radial velocity, which will fall at a tangent to the arc and results in a 'penetration angle' of about ninety degrees. This is not good since it is as though we cut a loaf of bread by pressing straight downwards. The centrifugal force being countered by centripetal force.