PhilosopherKing...Followthrough length, or what we call a "finish". is different for each person, and is based on several factors, such as bridge lenth, grip position, and how a person's arm works with their body, with no involvement of the shoulder. Involving the shoulder (elbow drop) leads to problems with timing and accuracy. Some pros are very effective with this technique...others have decided that a pendulum stroke is more efficient and accurate.
To your second question, that depends on the shot, but for most SOP shots, yes the backswing ends when the tip is pulled back to your bridge hand. Then you must have a smooth accelerated forward stroke which for lots of players ends with the grip hand on the chest, and the tip pointing down at the end of the stroke (some tips will be on the cloth, some just slightly angled down...depending on how high or low you stand over the cue). All of these measurements, and more, are part of one's personal shooting template. Naturally there are some shots, especially very soft finesse speed shots, where you still pull the tip back to your hand, but you modify your bridge length, and modify your grip position on the cue, to facilitate these kinds of shots
Scott Lee
http://poolknowledge.com
Scott Lee
http://poolknowledge.com