Many players nowadays have a two-handed backhand groundstroke. The questions is "when should I hit the two-handed versus a one-handed backhand, such as a chip or under spin?"
Whenever the shot is too far away, too wide, too short, too close and fast (jamming you), try the one-handed chip. Whenever the shot is too easy (you can get to the ball easily and you are not being pressed) use your two-handed backhand.
In general, if you are being pressed and are in a defensive position, use the one-handed backhand. If you are not being pressed and are in the offensive position use the two-handed backhand.
Good luck on the courts!