[Daryl]

I'm still a little confused.

How does this information mesh with leaving the face at practically 90 degrees?

Seems as if they are opposite.

One going down and one going up.

The direction of the ball will be the resultant of the Vectors of the forces acting on the ball, unless all the forces can be focused on one line (2-C-1 #3). The direction control would be stabilized and in addition, the ball would be propelled by the sum of the forces acting on it, instead of the much smaller Resultant Force of scattered Vectors.

The Rebound Direction is at 90 degrees to the Line of Compression. The Resultant Force is a combination of Line of Compression and Rebound Direction. The Initial Line of Flight will be along the Resultant Force.

But, The Rebound Vectors will be scattered unless the Line of Compression is focused on one line. So, The LINE OF FLIGHT (Resultant Force) depends on the "Quality of Compression" (new Daryl Term). That's one reason.

Another reason why the Line of Flight "Won't become at Right Angles to the Clubface" is Ball Location. There is only one Ball Location that can produce a Line of Flight at Right Angles to the Clubface.

The following is another reason:

The law of “Equal and Opposite Reaction” (2-L #3) also means that the flatter the Clubface angle (high numbers) the less the Clubhead will be slowed by Impact forces but the more it will be driven toward the ground (divot) and vice versa with the steeper Clubface (low numbers).

There are more reasons why the Ball won't leave the Clubface at 90 degrees:

2-D-1 MAJOR DIRECTIONAL FACTORS listed below (with references numbers) occur with unintentional or uncompensated changes in Component Variation or execution form Pattern (12-1, 12-2) or Address (3-F-5) configuration. Use 12-3.

1. Power Package Component Action (6-H)
2. Pivot component Action (7-3, 7-13, 7-16)
3. Power Package Component Position (7-
4. Pivot Component Position (7-12)
5. Plane Line Direction (10-5)
6. Bent Plane Line (4-D)
7. Angle of Approach (2-J-3)
8. Address Position Impact (7-
9. Off-Center Impact (2-F)
10. Lob Shot Impact (2-C-3)
11. Lag Pressure Point (7-11)
12. Clubhead Throwaway (6-D)
13. Tilted Clubface (2-D)
14. Plane Angle (2-N)
15. Ball Location (2-N)
16. Aiming Point (6-E-2)
17. Clubhead Speed (7-10)
18. Club Number (2-J-1)
19. Timing (6-F)
20. Grip Type (7-2)
21. Wrist Roll (2-G)
22. Steering (3-F-7-A)
23. Quitting (3-F-7-B)
24. Bobbing (3-F-7-C)
25. Swaying (3-F-7-D)
26. Rhythm (7-10)

So,"Practically at Right Angles" is a pretty good Term, especially because we know when and why and where and How it won't be.

Lastly. Club makers move the Center of Gravity around like it's a tool to make the average player get the ball into the air. This really screws with the Line of Compression when the center of gravity of the Clubhead is down near the sole of the club. Look at the Illustration in the previous Post with the Clubhead at Impact. Ideally, the Center of Gravity of the Clubhead will be on the same Angle of Approach at the moment of Impact and remain on the Angle of Approach through Separation and Low-Point.