There is an old trick question which asks how a player may make a century break after potting the white with his first stoke. The answer is, of course, that his first stroke is a ten shot. He then proceeds to screw in-off the spotted red and double the red into the bottom pocket for a six-shot. This counts as one hazard. He repeats this stroke up to the fifteen hazard limit thus scoring ninety from the red which when added to his ten shot, makes a century break!
However:-
A player commences on a red ball break and scores 63 points by making twenty-one red ball hazards. He has not played any six strokes; he is not penalised in any way, and at the end of the break these points are added to his score. His opponent has no redress. How may this come about?