Dr. Dave's FAQ says Hal Houle's 3-angle system is considered the original version of CTE, then lists later variations, including Shuffett's. Some forum users insist the 3-angle system is a separate method, and we found no reliable record of who first used the name. The numbering below is the FAQ's.

These instructions do not mix. Pick one source and stay with it until the routine is stable.

Inside and outside are named relative to the cut: inside is the side of the ball toward the cut direction, outside the side away from it. A and C stay put as the left and right quarters.

CTE line

From the center of the cue ball through the outside edge of the object ball.

A

Left quarter of the object ball: inside on a left cut, outside on a right cut.

B

Center of the object ball on every cut.

C

Right quarter of the object ball: outside on a left cut, inside on a right cut.

The geometry is familiar. Put the inside edge of the cue ball on A and the balls overlap by 3/4 of a ball; on B, by 1/2; on C, by 1/4. Those are the standard hits of fractional aiming, and shot as plain fractional hits they give cuts of about 14.5°, 30° and 48.6°. The 3-angle system called them 15, 30 and 45, which Dr. Dave notes is not exact at 15 and 45. The offset and pivot then move the final line off the sight line, so no chart angle carries over directly.

This is the fixed-bridge form, which is the easier one to check. Start with center ball and no intentional sidespin.

1. Read the shot standing up. Identify the cut direction and choose a category from the table below. The system gives no direct rule for this; the FAQ says the judgment comes from practice and experience.
2. Sight the CTE line. Look through the center of the cue ball to the outside edge of the object ball.
3. Add the second visual. Shift to a line from the inside edge of the cue ball to the point for that category, holding the CTE line in view. On thin cuts, drop the CTE visual and just sight the 1/8-ball overlap.
4. Drop in and set the bridge. Slide straight toward the cue ball, placing your bridge so the cue sits half a tip off center on the side the table calls for.
5. Pivot to center. Keep the bridge hand planted and swing the back of the cue until the tip addresses center ball.
6. Stroke. Deliver straight through along the new line. The FAQ's procedure ends at the pivot; pausing first is our own suggestion.

That table reflects the FAQ's reading of the DVD. With the balls under about 1 ft (30 cm) apart, it swaps the inside quarter for inside 1/8. Shuffett later added C on left cuts and A on right cuts as thin-cut aim points, and changed the visual for near-zero-angle shots with the balls more than a diamond apart, so check his current material.

Bridge length follows ball separation. The FAQ gives 8-9 in (20-23 cm) over 2 ft (61 cm), 7-8 in (18-20 cm) at about 2 ft, 6-7 in (15-18 cm) at about 1 ft (30 cm), and 5-6 in (13-15 cm) under 1 ft. The pivot is small, which is why this matters. On a 12.5 mm tip, half a tip is about 6 mm (1/4 in). By our arithmetic, that turns the cue about 1.7° over an 8.5 in (22 cm) bridge and about 2.6° over 5.5 in (14 cm).

Pro One proper leaves the mechanical pivot behind. The FAQ describes it as a level of ability where bridge placement and center-ball alignment come naturally, without a fixed-bridge pivot. Players on the AZBilliards forum call the move a visual sweep.

For. Alciatore, who teaches his own method, still writes that aiming systems help some people aim, concentrate, stay down and shoot better. He also says Version 4 should generally work better than earlier versions when followed literally, because it has more alignments and less pivot. Shuffett's site publishes student testimonials, which are reports of improvement rather than tests.

Against. A fixed set of alignments at a fixed distance yields a fixed set of cuts. As Alciatore's 2008 Billiards Digest column explains, shots between the available lines of aim need compensation. A literal, unadjusted routine will miss some of them unless the ball is close to the pocket or the pockets are large.

The reply. In an exchange quoted on Dr. Dave's site, Shuffett says two shots can share the same visuals without the eyes being in the same place, and that eye position alters perception. Asked what guides the eyes, he answers: experience. Skeptics call that feel. We found no controlled study on either side.

The alignments and pivots don't do the aiming for you.

— David Alciatore, on how CTE Pro One works in practice

The useful conclusion is modest: CTE can be a good framework for seeing and committing to shots, and the fine adjustment still has to come from you. Our guide to a pre-shot routine covers the part of that benefit you can get without any system.

The first and third drills come from Dr. Dave's evaluation page. Log positions by diamond numbers or a phone photo instead of marking the cloth.

1. Run the menu. Cue ball on the head spot, object ball 2 ft (61 cm) ahead on the center line. Ignore the pockets and shoot the six left-cut combinations: A, B and 1/8, each with a left and a right pivot (a right pivot starts with the tip right of center, which is outside on a left cut; a left pivot starts left of center, which is inside). Reset each time and note where the object ball meets the cushion. A careful player should get a repeatable direction for each.
2. Mirror it, then change the distance. Repeat to the right, remembering that A and C swap roles. Then move the balls closer and farther apart, adjusting the bridge, and watch how far each direction moves.
3. Shoot the in-between shots. Set up cuts of about 10°, 15° and 20° at one separation. Ask what you changed to pocket each: eye position, offset, pivot amount or effective pivot length. That answer is your real system.
4. Separate aim from stroke. Use a striped ball as the cue ball with the stripe vertical. If the stripe wobbles, you are adding sidespin, so fix your stroke before you touch the visual. Cut-induced throw and speed also cost balls; see our guide to squirt, swerve and throw.