Thanks John. I have been looking and seeing, but I just don't have the confidence to go for it when I'm playing. It will come. Are there training books that cover cluster analysis or do you just get it from experience?
Trust is the 1st part of this meaning trust in what you are seeing you have to trust that a ball frozen to another is going to go straight along the tangent line every time, you have to trust that a frozen ball is going to be pushed in the same direction as the CB, you have to trust that that ball is going to go off that other ball and into the pocket.
So 1st you have to learn how the physics REALLY work (BTW you would not believe the category of player that does not know, some of these guys that don’t know are outstanding pool players) Then you have to look for these shots; then you have to trust in what you have seen. Here are a few “tips” that might help.
1. Bury your nose in the rack when you are examining it; the difference between frozen and .1mm can make a difference.
2. Look at the potential cluster shot from both sides; in other words from the OB to the pocket and from the pocket to the OB. You will be amazed at how often it looks like it will go from one side and not the other.
3. Look at all of the balls orientations; not all balls need to go straight in. If you see a ball that goes into another ball check to see if that goes into a pocket.
4. Don’t discount banks, the margin of error for a bank shot is usually higher (if only slightly) when you have it part of a cluster shot (that’s good it means you can make a bigger error and still have the ball go in) why? Because the ball is hitting another ball into another ball; so the human error factor is reduced, If you missed it probably wasn’t your technique it was probably you initial analysis.
5. It may take several looks at several different angles to determine how the force will be transmitted through the rack. If another ball knocks your intended OB out of the path going toward the pocket this was your mistake 99% of the time; you didn’t read how force is being transmitted through the rack properly.
Those are the grass roots I don’t know if that is too simple of too complicated or just right for you because I don’t know your background. Like anything there is no substitute for experience with these shots. If you have even an inkling that you do not understand some of the underlying physics; if you are ever unsure about why a ball reacted a certain way this is the 1st problem that you should address. I suggest Byrns Standard Book of Pool & Billiards; there is a good section on cluster analysis in there also.