Rules Quiz 4.

Question 4.

Someone you play starts their serve by running from the back corner jumping forward into the service box and doing an overhead tennis serve - is this allowed?

Answer to question 3 (racquet throwing).
For a shot to be valid, the racket must actually be in your hand at the moment you hit the ball. (It is up to the Referee to decide if the racket was in fact in your hand). So the answer to Question 3 is that you don't win, and it is not a let, but in fact you lose the rally - never mind that it was a winning 'shot'.

You must be careful not to throw your racquet in a dangerous way that might hit your opponent. The referee can give penalty points and games against you for this sort of dangerous or agressive play (Rule 17). Also, if you throw or drop your racquet when it is the other player's shot then you could lose a point if the action or noise of the racquet hitting the floor distracted them (Rule 13.1.3).