Intuitively, this makes sense.

Since the hand cannot
move forward a distance greater than the length of the arm, it must have a velocity of
0 at full arm’s length extension. It follows that the hand must decelerate well before
the arm is fully extended. Advising beginners to attempt to hit an imaginary target
25% of their arms’ length on the far side of their targets would therefore be more
precise than the typical encouragement to aim for the floor, but the physical principle
is the same: maximum hand velocity is achieved when the point of focus of the strike
is well beyond the surface of the target.