Unless "chin" is signaled, "high" usually begins when the guard with the ball waves the other one through.

5 rubs off of the cutting guard to the elbow.

If the guard waves 2 through to bring the post to the elbow to begin "high", 1 doesn't always have to pass to 5.

He may choose to spin and dribble instead at 4 to initiate a backdoor/fill or flare option.

If 1 passes the ball, he uses 5's flare screen.

Top flare situation begins.