The time your game is most vulnerable is when you're ahead; never let up.
Roger Federer certainly is my claim to be the best of all time - if there is such a thing. With Rafael Nadal not far behind.
I like to let my racket do the talking.
The next point - that's all you must think about.
An otherwise happily married couple may turn a mixed doubles game into a scene from Who's Afraid of Virginia Woolf.
When you have the opportunity, you strike.