To play any game well, you have to have a clear grasp of what the game is about, what the objective of the game is, what counts as winning, and also plenty of practice. But it is also helpful to listen to advice, for there are quite a few useful principles and precepts. They will not be useful, however, unless taken in the spirit they are given.
For instance, it is a useful bit of advice in tennis to say “Keep your arm fully extended and do not bend your elbow too much”. But there are plenty of occasions, when you are up at the net, for example, when this advice should be disregarded, and it is impossible, for the coach to make a complete list of these exceptions, because so much depends on the individual player, on his opponent, on the conditions of the court and so on. The person being coached must certainly not disregard this advice, but neither must he take it too seriously, or think that if he always follows this advice he will necessarily play good tennis.
He must learn to take the advice in conjunction with practice in playing the game itself, and consistently move back and forth from the advice to the actual situations he meets on the court. Only by doing so, will the player get the most out of the practice or advice.