The ego of the coach must not interfere with the decision-making process. I believe intensely in passion for the job and that the will to do the detail is the difference between good and excellent.
Preparation is the key to sustained success, because preparation allows a coach to apply his/her knowledge in useful chunks.
Knowledge is useless if not delivered and applied in the right way. Often it is not what you say, but how you say it. The more you know, the less you say and timing becomes everything.
Both player and coach must become comfortable with being 'uncomfortable', because staying on the edge of performance means pushing constantly for improvement.
The most important person for the athlete is the coach, who must be an expert in the technical and tactical areas of coaching and also be very knowledgeable in all the other departments, so that the right team of people are in place.
The coach also needs to be able to make decisions based on pooled knowledge and can only do this effectively if he/she has the experience and expertise.
The modern-day professional tennis coach is a manager of young people's professional lives and aspirations and therefore must keep abreast, or even pioneer, cutting-edge research.
by David Sammel