[drewitgolf]

2-C-1 depicts Dual Horizontal Hinging and its closing only motion, as opposed to 2-C-2 Dual Vertical Hinging and its Lay-Back only motion.

Look at 2-C-1 #2B, notice the Impact Point is not the back of the ball, but the inside aft quadrant. When the ball leaves the Club Face, however, at Separation it is at a different location and the club face is now at right angles to where the ball leaves it. Impact and seperation are at two different places, about 3/4 of an inch difference.

Notice in 2-C-1 #2B that the center line does not point down the flight line, it points to "right field", just as it does in 2-C-1 to take into account the closing motion between Impact and Seperation.

Go to 2-C-2 and notice because there is no closing of the Club Face, the Center Line for both Impact and Seperation are both straight lines.

Hope this helps.