Almost all aiming systems work! Minor detail, the shooter has to be able to adjust to current conditions. Many years ago somebody at Greenway was steering road players at me and a few told me I was in their "book" of local players that road players swapped information about. The little bar I could be found at early and late was tiny, two bar tables and a narrow bathroom filled one side of it front to back! With doors by both tables weather conditions were a major factor. More important on the really tough shots, the side light on those tables was very close to as strong as the overhead light. Took me several months to figure out that lighting made the balls appear slightly to the south side of where they were. Didn't matter until you were shooting a razor thin cut or a long bank, then you were apt to miss just enough to keep a ball out of a pocket! I burned at least a handful of road players on those tables. I suspect that like me when I first played those tables they thought their game was a little off without understanding why!
Even today I watch for gaff conditions like a HVAC vent blowing on a table and try to never shoot on a table near a door. Another wicked old table had been moved to the front of a bar to pull in customers showing in a big window. For a couple hours in the afternoon one whole long rail was a safety zone! You bent over to shoot cross table and looked directly into a blazing sun!
Aiming systems are wonderful things, as long as you understand how to modify them.
Hu