If a shooter can consistently shoot the shot, they know the shot line. They can use any system, or no system other than HAMB.
Finding the shot line is pretty easy but requires practice, just look at the pocket and follow the line from the part of the pocket you want (or carom target etc) to the OB. That's your aim line. Shoot the shot. It's like any system, it takes table time to do it, but it's the most simple method you could ever use for finding the correct shot line and where to hit the OB.
The OB isn't physically divided into segments or fractions, it's a physical sphere that you're hitting with a physical sphere. Hit it so it goes down the aim line. There isn't a lot of need to divide the OB or CB into segments/fractions/edges, treat it as one sphere and hit it where it needs to be hit with the other sphere. I'd rather hit the ball exactly where it needs to be hit than mess with trying to visualize fractions. There is one aim point on the ball from an infinite number of "points" on the ball. If you hit it there in the correct manner, it goes in. You learn the correct manner and adjustments from practice. Always stay down on the shot and learn what the CB and OB is telling you.
The whole key is focusing and not losing your visual focus on your aim line. Study the sphere. Take the place you need to hit it and burn it into your mind. While taking the aim line while standing and looking at OB, you should account for throw and what the effect of your english will do. You pick the part of the pocket that is the most forgiving for each particular shot. Pockets are larger than the ball so target it in a way that gives you the most "fudge" room.