"Change can be essential, but it should only be made with careful consideration and just cause. Losing can persuade you to change what doesn't need to be changed and winning can convince you everything is fine even if you are on the brink of disaster. If you are quick to blame faulty strategy and change it all the time, you really don't have any strategy at all. Only when the environment shifts radically should you consider a change in fundamentals."
Garry Kasparov em "How life imitates chess"