Frame #D -- Pre-Launch Mechanics
The batter has almost finished his soft stride. The lead-foot is nearing toe-touch and most forward body movement has stopped. The back-elbow rises as the batter continues to accelerate the bat-head back toward the launch position by pulling the hands (mainly with the top-hand) toward the back-shoulder.
Hank Aaron & George Brett's Swing Mechanics
Pre-Launch Torque & Wrist Bind - Bond's Mechanics
Weight-Shift and Body Rotation