I'm not sure if anyone has ever discussed this in any detail, so I thought I would try. If nothing else, those who pivot-aim will find it interesting.
It's obvious no secret on here that I'm a pivot aimer. People PM me all the time asking in private which system is the best. I always try to tell people that it depends on how they perceive and how they learn. Some people pick up CTE/Pro1 right away and others can't get comfortable. The same people try Ron's 90-90 and voila - they pick it up right away (or vice-versa).
I think I'm lucky in the fact that I picked up all of them fairly quickly and have spent thousands of hours over the past four years mastering them and figuring out why/how they work. The conclusion I'm come to is: they are all identical at their core. Only the pivot direction and base reference changes from system to system.
Personally, I think learning how to pivot aim has been the single strongest thing I ever learned in pool - and there really isn't a close second.
First, some basics:
CTE:
Center-to-edge (CTE) is a pivot aim system that uses the CB center to OB outside edge line as it's base reference. While sighting this line, the shooter bridges from an offset position and pivots back to the CB center. When executed properly, the result is the solution for the shot.
Pro1:
The same as CTE, but allows the shooter to always pivot from the same side. For right-handers, this includes left-to-right pivots and for left-handers this would be right-to-left pivots.
Ron Vitello's 90-90:
Ron's system uses three sighting reference lines: CB inside edge to OB inside edge (called 90-90 alignment), CB inside edge to OB center (called 90-half alignment), and CB inside edge to OB outside edge (called 90-reverse-90 alignment). The shooter aligns their cue to an above reference line and hip-pivots their way to the center of the CB.
Therefore, the core difference between the systems is that CTE/Pro1 is based on visual references such as the center-to-edge line (CTEL) and identifying the outermost edge; whereas Ron's system is based on cue alignments (I would call it stick-aiming with a pivot).
Let's talk about a thicker cut to the left (more than a 1/2 ball hit). With Pro1, the shooter probably sees the shot something like this:
I put these balls on a grid so you can get a feel for the table rotating as you move around the CB - NOT because it's "part of the system."
A mistake a lot of players make is to look straight down the CTEL. One really must accurately identify the CTEL by looking across it slightly. When you move your body to the outside (technically, moving your head to the outside), your vision of the shot rotates around the OB as the center. Your new view of the shot is this:
As you step into the shot as a right-hander, your cue is at the left edge of the CB and you're pivoting to center (blue line):
When you look at the 90-90 cue alignment, you'll see they're nearly identical (edge-to-edge).
Let's check out a thin cut to the right - something less than a half-ball hit.
With CTE, the shooter sees something like this:
The shooter's body/cue is positioned on the right-side of the CTEL at the CB edge (blue line) prior to pivoting. It's also a 90-half alignment with Ron Vitello's system.
The pivot motion was never really discussed in detail until a year or two ago. One would quickly figure out that you can't rotate the cue in your bridge (as if there were a nail through the wood and into the table where the cue touches your skin-- a true rotation). By doing so, you either miss the ball completely or end up hitting the OB square.
With CTE/Pro1, the distance of the shot determines how one pivots along the shot arc (the arc of a circle formed with the bridge as the center and OB as the edge). With Ron's system, one would "hip-pivot." When you get within a diamond or so, the shooter will sometimes have to go from a 90-90 alignment to a 90-half alignment when hip-pivoting. The reason for this is when you hip pivot, you're performing a flatter arc - which is in fact a CTE pivot for a longer shot. Because you'll undercut a close-quarters 90-90 shot, the 90-half alignment is required to pocket the ball with a hip-pivot.
Hip pivoting is really repeatable and is a super technique--- I use it with "this system" except in close quarters. Instead, however, of making a sighting adjustment, I simply pivot my back hand and hip at the same time (I like to keep eye/cue alignment) and make a "harder/curvier" turn to center--- paying close attention to the shot arc. Once you understand the proper bridge placement (bridgehand spot - a Jim Scott term) and understand how to arc your pivot - many don't pivot at all----they "air pivot" by rotating along the shot arc from the bridge point while standing up and slide up to the CB along this line.
I'm not going into all of the other overlaps because this post would take me all day to make and all day to read. I'm merely throwing it out there for those who may not know - and letting them experiment on their own.
In conclusion, they're all the same system. Their methods might differ slightly and they're taught differently; but they are the same. After all of this, I'm in awe of guys like Ron and Stan for really innovating when it comes to this stuff.
With Ron, he didn't even know CTE before he made his system which is really, really amazing to be able to come up with that on your own. Not to mention coming up with the "hip pivot."
With Stan, to recognize that it was possible to always pivot from one side is amazing as well. However, even though he was the first (from what I know) American to pivot from the same side - guys like Bustamante were doing it all along.
How Hal came up with this core information is mind boggling (just my humble opinion).
Hal used to always tell me to poke my head out to see the outermost edge... and I never really understood what he was trying to tell me until a year or so ago. That's what clued me into looked across the CTEL rather than down it. Interestingly enough, if any of you play with Perfect Aim and are knowledgeable with the above-mentioned systems, you'll discover his eye placements are equal to the CTE head position required to sight the outermost edge. Gene is finding his overlap from this position --- he just finds the solution in a different manner.
All in all, each method is almost like a limit to a core equation. Or, a dialect to the same language. The more dialects you know, the better you can communicate on the table - if that makes sense.
I understand there is a large group of people who would read this and say "why?" Just put it in the hole. The answer is because the foundation is a repeatable pre-shot routine that sinks every shot. The foundation is formed by identifying perceivable points instead of using intuition (which can sometimes fail). Over a period of time, the foundation manifests from something mechanical-feeling (when new) to something quite natural and second nature (feel). The difference being that the feel you experience with this information is less fallible because it's based on definitive points that are easy for all to perceive.
Anyways, it's late now and I've been typing for a while. I hope those who are experimenting with this type of stuff find it useful. Sadly, I'm sure the usual suspects will derail the thread. I'm not interested in debating the systems, I'm not interested in instructing on the hows/whys of the systems, I'm not interested in arguing in general. I may not even post anymore in the thread because I know how I get. Just wanted to put out some good info since I haven't in a while.
Spidey
