They are trying to psych you into hitting all your shots to their back hand, so they have less court to cover. Hit to their forehand to open up their back hand. They will usually go inside out to your back hand, forcing you to go back cross court with your back hand to their inside out forehand. The first short back hand should be struck down the line to their fh. Then you cover the cc shot to your fh. Then take your fh dtl to their bh it the shot is there. If it's not, then you go back cc to their fh. Disguise also helps. If you show them that you are going inside out to their bh, they will cheat to that side, esp. if their bh sucks.