Yes, that's true. But my question is how one initially determines the point to aim at? It must be the mirror image point.
~Doc
Doc, I went on line to Billiards; Mirror Image Aiming Method, and there are a few videos by Dr. Dave. In this case that PJ posted, the method used is to measure from the center of the ob to the diamond line and double it. From that point to the cue ball is the aiming line. The extra ghost ball as diagramed is of no real consequence and only adds another dimension of sorts, I guess for double checking by another method once the aiming line is established.
When the ob ball is closer to the rail another measuring method is used. And when not wanting to hit the ob square, yet another method is used.
I questioned the legality of using devices to measure or to check angles, and thus checked, and it is allowed in CSI/BCAPL when either banking a ball or kicking, but not allowed to be used to measure gaps for ball clearance to pass a ball through. So in DCC using the cue or hand to measure bank and kick shots is legal. It is illegal to place a chalk or otherwise mark the aiming point, and the foul is automatic, no shot needs to be taken! In WPA; marking the table is unsportsmanlike conduct.
I am not exactly that comfortable with a player using their stick or hand to measure, I am ok with using it to site in a bank or a shot. I do know that WPA does not allow the stick to be laid upon the table without your hand on it to site a shot.
But I can not find any info. from WPA concerning measuring shots, so it is legal to do so. Whitey