these are the players that I can remember who might publicly acknowledge an especially great effort, or shot after a rally in a professional competitive match Men: Agassi, Becker, Gerulaitus, Noah, Rosewall, Cash, Roddick, Leconte, Federer, Connors Women: King, Evert, Wade, Navratilova, Seles, Sanchez, shriver, Hingis, Davenport Who am I missing? Let's not count one moment in 50 matches! These are the ones I noticed never did it. Men: Lendl, Hewitt, Chang, Borg, McEnroe, Women: Court, Austin, Mandlikova, Graf, Sabatini, Serena, Am I wrong so far? who would you add? and last does it bother you either way? Personally, as long as it its too showy or too frequent, I think it is occasionally a nice gesture, that shows a player isn't entirely self-absorbed or too hung up on 'match psychology' to show a little appreciation.