You think davis cup is the players only exposure to training? Pmac isnt a great coach either, he rode his brothers coat tails to where he is. Why do you think he doesnt coach any tour player? Who cares if someone has seen sampras play. Watching a match or a television doesnt make you more knowledgable about the game. I do find it amusing when people who obviously dont own a racket try to sell me something based on their fandom.