Replacing the cueball after a Miss:
Section 3, rule 14 of the Rules covers the 'Foul and Miss'
subsection f) states:
"After a Miss and a request by the next player to replace the cue ball, any object balls disturbed will remain where they are unless the referee considers the offending player would or could gain an advantage. In the latter case, any or all disturbed balls may be replaced to the referees satisfaction and in either case, colours incorrectly off the table will be spotted as appropriate"
Note that only the cueball and colours incorrectly off the table must be replaced. All other balls are at the referees discretion. Make sure that you let the player know which balls you intend to replace before he makes the call to replace.
Be careful to replace all balls that were relevant to the shot e.g. if, in attempting to escape to the pack of reds the player strikes an intervening ball, which often happens, that ball must be replaced accurately, since it is close to his intended escape path. Similarly, if in moving that intervening ball it, in turn, moves a possible ball-on into a more favourable position, then that, too must be replaced.
Replacing the cueball accurately is essential for both the referee and the player. It is not always good sportsmanship that drives players to get the cueball exact.
When they play their first attempt, they note where the cueball is and where they are aiming., so that if they miss, they know by how much and, everything else being where it should be, they can make the appropriate adjustment and be successful in the second attempt. This requires that the cueball be exact. If it is off, even by a minute amount, it can throw the adjust out of whack.
It also requires that the player knows exactly where he aimed. To do this, he does not try to aim for the same spot on the cushion, at that is nearly impossible to determine unless there is a chalk or other mark on the cushion to guide him. Instead, he once he is online, he will raise his aim and find a spot on the wall or elsewhere off the table that he can use to reproduce his aim. His subsequent attempts will not be aimed at the cushion, but at that spot on the wall.
So it behooves a good referee to carefully mark the position of the cueball if there is any chance of a Miss being called. If the player is in the way, ask him to move so that you can get a good grasp of the situation.
If the cueball is near a line, a spot, or a cushion it should be easy to remember where it was. This is especially true if it is near the baulk cushion because you can mark it mentally by realizing that, for example it is “two inches off the cushion directly in line with the B in Brunswick”.
Given that you think that a Miss is possible, the cueball will probably be behind another ball. From behind the cueball, look across the edge of cueball and the nearest edge of the snookering ball and find the extreme point that the cueball will hit on the cushion (or the wall) without striking the snookering ball. If you do this with both sides of the escape, you can put the cueball back exactly where it was, unless the snookering ball is moved.
Other than this, try not to line the cueball up with other balls on the table, because they do get moved, destroying your markers. Instead, line up the cueball with a spot, or edge of a pocket, again marking it it on a spot on the wall. Do this to both sides of the cueball. You should also be able to use the lines of the "D" to help you.
With the advent of cell phones with cameras, don't be afraid to to take a snapshot or two if the position is difficult to mark. Similarly, if a member of the audience if filming the frame, you might be able to commandeer it to accurately replace the balls.
When you have replaced the balls to your own satisfaction, ask BOTH players if they are happy with it. If not, ask them to point to where they think that it should be but DO NOT LET THEM TOUCH A BALL as this is a foul.
If they move it and both agree that that is where it was, even if you know it is wrong, then on any subsequent Misses, the new position is where the ball is returned to. They both agreed, so now they both play the table as it sits.
When you have replaced the balls to your own satisfaction, ask BOTH players if they are happy with it. If not, ask them to point to where they think that it should be but DO NOT LET THEM TOUCH A BALL as this is a foul.
If they move it and both agree that that is where it was, even if you know it is wrong, then on any subsequent Misses, the new position is where the ball is returned to. They both agreed, so now they both play the table as it sits.