Since LinDan does it every time, it's part of his style. If a person has a totally impassive face, they get criticised for being impassive. The trick is the psychological game. A game is not only about skill. It is about how you use that skill. Same with academic exams, interviews, debates etc. Sports psychologists recognise it as tactics Sure it is a trick. Others use some to great effect. Football is a great example - they spit or swear at opponents to invoke a physical reaction. One guy use to grab at the groin area of his opponents (Vinny Jones). Even Ruud VN jumped all over Patrick Viera (I think). Physical confrontation is over the borderline IMO. But before that... Just on a last note. If a person gets disrupted by such behaviour from his oppponent, I take it as a sign of mental weakness. It happens at all levels of play. The answer is not to cry and say "foul play". The answer is to become mentally tougher. Only the winners get remembered.