The catch is everything. The bar hangs at your thighs. Bend your knees slightly, then explode upward with your legs and hips, shrugging your shoulders hard. The bar accelerates upward. As it rises, you pull yourself under it with your elbows high and drop into a quarter squat or as deep as your strength allows. The bar lands across your shoulders, never your neck. Your elbows punch forward and up. Catch the bar, stabilize, then stand up. The power phase is brief; the catch is where the movement is learned.