Has a long swing which loops under the ball -- a bat drag position. I would do two things. First minimize the over rotating (spinning) of the lower half. Close the front foot and minimize the back foot from spinning. Second focus on letting the hands go directly to the hitting zone while maintaining control of the bat. Don't let the back elbow lead the knob. Concentrate on barreling the ball. It is ok to start by hitting a ground ball. It is important that your son gets control of the bat. Good luck.