I have never read that a defender must establish LGP before a shooter begins his shooting motion. I have always thought it must be established before A1 gets airborne. I've been wrong all these years? If so I would really appreciate a word-for-word citation so I can stand corrected.
Here is the college rule, I guess HS rules are different in regards to airborne shooters
Rule 4-35:
Art. 4. To establish an initial legal guarding position on the player with the
ball:
a. The guard shall have both feet touching the playing court. When the guard jumps into position initially, both feet must return to the playing court after the jump, for the guard to attain a guarding position.
b. The guard’s torso shall face the opponent.
c. No time and distance shall be required.
d.
When the opponent with the ball is airborne, the guard shall have attained legal position before the opponent left the playing court.Exception: (Men) Rule 4-35.7
Art. 5. To establish legal guarding position on a player without the ball:
a. Time and distance shall be required to attain an initial legal position;
b. The guard shall give the opponent the time and distance to avoid
contact;
c. The distance given by the opponent of the player without the ball need not be more than two strides; and
d.
When the opponent is airborne, the guard shall have attained legal position before the opponent left the playing court.