I played table tennis many years ago and I was told that it is the lower part of the bat a little off the center to contact the ball for topspin. for badminton a little off the center toward the head is the best contact spot. for tennis I have a feeling that if I contact the ball at a little off center at NE/SE(divide the racket face into four sections with hitting side facing ground) for right-handed FH topspin I feel good. if contact at NW/SW, it is really bad. for underspin, NE/SE are bad and NW/SW are ok. of cause I really can't see where the real contact is. I just try to aim at that area and feel it as what the "Inner Games" said. my question is: is the center the best contact spot? your opinions are greatly appreciated.