[Trig]

Either the Left Arm (Pull / Swinging) or the Right Arm (Push / Hitting) is the Active Direct Drive of the Basic Motion Stroke. The other is Passive and supplies merely motion. But, no matter which supplies the Active Direct Drive, the Left Arm swings and the Right Elbow bends.

The Active Direct Drive is the player's choice per the Basic Patterns of 12-1-0 (Hitting) and 12-2-0 (Swinging). A bystander cannot tell which Force (Pull or Push) is being employed. Study 10-11-0-1 and 10-11-0-4.

Got it. Depends if you Hit or Swing! Duh!