Setting Up the Test

Place the cue ball on the brown spot and address it directly down the centre line of the table towards the black spot.

First, establish your straight line

Play the cue ball through its centre with a normal, straight delivery.

The cue ball should travel down the line of the spots.

Repeat this until you're satisfied that you're delivering the cue straight.

This gives you a reference point before introducing side spin.

Now Apply Side Spin

Set up exactly the same shot again, but this time apply either left or right side.

I recommend striking the cue ball at approximately 3 o'clock or 9 o'clock, roughly a tip width in from the edge.

Keep the Test Consistent

For the test to tell you anything useful, you need to reproduce the shot as consistently as possible.

Try to maintain the same:

• Amount of side
• Tip height
• Cue speed
• Cue elevation
• Bridge position
• Cue delivery
• Starting position

Repeat the shot several times using both left and right side.

You're looking for repeatable behaviour, rather than judging the cue from one individual stroke.

This matters because cue-ball deflection testing can be affected by several variables. Squirt and Cue Ball Deflection specifically identifies speed, tip contact height, tip characteristics, cue elevation and other factors when discussing deflection testing. [drdavepoolinfo.com]

How Hard Should You Play the Shot?

For our practical test, I like to use approximately lag pace, with enough speed for the cue ball to travel down the table and return towards the baulk end.

The most important thing isn't achieving one absolutely perfect speed.

It's repeating approximately the same speed each time.

Changing the speed can alter the overall path you observe because you're potentially seeing a combination of cue-ball squirt and swerve rather than squirt alone. Squirt, Swerve, and Throw Confusion explains that swerve is influenced by shot speed, shot distance, sidespin, cue elevation and ball/cloth conditions. [drdavepoolinfo.com]

Keep Your Cue as Level as Possible

This is particularly important.

Try to keep the cue as level as the table and shot allow.

An elevated cue combined with sidespin can introduce additional swerve, making it harder to distinguish the cue's initial deflection from the subsequent curve of the cue ball. Squirt, Swerve, and Throw Confusion distinguishes squirt from swerve and explains that cue elevation is one factor affecting swerve. [drdavepoolinfo.com]

We're trying to create a repeatable comparison, not a laboratory measurement.

Keep the Strike at Centre Height

Try to apply your left or right side at approximately centre-ball height.

Don't deliberately introduce screw or follow.

Again, the objective is consistency.

If one shot is struck above centre, another below centre and another directly through the horizontal centre line, you're changing more than one variable and the comparison becomes less useful.

Squirt and Cue Ball Deflection specifically identifies tip contact height and draw/follow effects among the considerations involved in cue-ball deflection. [drdavepoolinfo.com]

What Are You Looking For?

Watch how far the cue ball initially moves away from your original line when side is applied.

With:

That distinction is important because the cue ball may subsequently swerve back towards the other direction during its journey. Squirt, Swerve, and Throw Confusion defines squirt as the initial angular displacement away from the cue's stroking direction and swerve as the curve occurring afterwards. [drdavepoolinfo.com]

Repeat the test enough times to establish a pattern.

Don't Become Obsessed With an Exact Measurement

This is one area I'd change from our old advice.

I wouldn't now categorise a cue as:

The test contains too many variables for those measurements to be universally reliable.

Different speeds, tables, cloth conditions, tip positions and cue elevations can change the result you see. Squirt, Swerve, and Throw Confusion [drdavepoolinfo.com]

Instead, use the test to compare cues under the same conditions.

That's considerably more useful.

A Great Test When Changing Cues

This test becomes particularly valuable if you've played with the same cue for many years and are looking to replace it.

Test your old cue first.

Then, under the same conditions, test the new cue.

If the new cue produces a noticeably different reaction using the same amount of side, you've discovered something that the basic specifications won't tell you.

You may have:

• the same 9.5mm tip,
• the same 18oz weight,
• the same 58" length,
• and a similar balance point,

but the two cues can still behave differently off-centre.

That difference may help explain why the new cue initially feels unfamiliar.

What About the Tip?

The condition of the tip should also be considered when making comparisons.

For our own practical testing, I prefer the cue to have a properly fitted, shaped and settled tip so we're comparing cues under sensible playing conditions.

If you're comparing two cues, try not to change several variables at once.

For example, comparing an old cue with a well-used tip against a new cue with a freshly fitted tip doesn't isolate the shaft alone.

What Does the Test Actually Tell Me?

It's important to be realistic.

This isn't a scientific laboratory test and it doesn't produce an absolute "deflection rating" for your cue.

What it does give you is a practical indication of how the cue reacts to off-centre striking.

That's extremely useful when comparing different cues.

For example:

1. Test your existing cue.
2. Test another cue using the same setup.
3. Keep your speed, tip position and delivery as consistent as possible.
4. Compare the resulting cue-ball paths.
5. Repeat several times using both left and right side.

You're now making a meaningful like-for-like comparison.