Effective coaching requires a huge personal and emotional commitment from the coach, which leads to a pseudo-mental adoption of the players by their coaches.
Coaches like to refer to the players they are coaching as “my players,” which connotes some sort of ownership. In the same way, they like to use the phrase “He stole my player,” which implies that someone took something that belonged to him.
The truth is that players will seek your expertise as long as you are providing what they need at the time and will change training venues as soon as they believe someone will offer them a better training environment.
It is a competitive business, and players are always looking for an edge. Many factors influence a player’s decision of where to train: number of athletes in the program, level of play, age of the participants, ratio of players to coaches, the facility, the schedule, convenience, coaching style and other personal considerations.
As a coach it is important to keep this in mind and make decisions knowing that most players are just passing through your program, especially if you do an outstanding job. If you decide to spend your own resources to help a player, keep in mind that even if you have a contract with the player, there is always a good chance the player will leave your program sooner or later.
Realistically, it is very difficult for a coach to offer the best training environment throughout a player’s career. As players get older and better, their needs are totally different. They will have to travel much more, and it will be increasingly difficult to find training partners at their level of play.
It is never easy for any coach when a star pupil leaves because of the tremendous investment required to develop a top player, but it is part of the job as a high performance coach.
Players will leave. Do not take it personally. They are never your players!
From the book "Developing High Performance Tennis Players"