My son (now 10) started playing tennis at 4y.o. He choked up on the racket with his dominant hand and used his left hand for balance. He has a 2 handed forehand/backhand (dominant hand at top). He's learned to really stroke the ball over the years. Now I signed him up for a tennis class (hoping it will fuel the tennis fire in him.) But the class instructor wants him to change grips and hit a 1 handed forehand. The result is my sons ability has dramatically dropped and he is frustrated playing with people he would easily beat before. Now my son wants to quit. I tried (unsuccessfully) to switch his dominant hand to the bottom more than once in the past but figured it was like golf...whatever grip your comfortable with as long as you're on the proper swing plane. When I spoke with the instructor about this, he was dead-set on switching my sons grip. Any advice?