What is squerve?
Squerve, sometimes called “effective squirt” or “net cue ball deflection,” is the combined effect of SQUirt and swERVE. For more information, see “Squirt – Part VIII: squerve effects” (BD, March, 2008) and “Squirt – Part III: follow/draw squirt and swerve” (BD, October, 2007). For a summary of all of the factors affecting squerve, see: squirt, swerve, and throw effects. Also, here’s a video excerpt from Vol. II of the Video Encyclopedia of Pool Shots that explains and demonstrates things:
One way to compensate for squerve when aiming a shot is to use back-hand english (BHE), front-hand english (FHE), or a combination of the two, as described and demonstrated on the BHE/FHE resource page. For the following discussion, see the diagram below from Patrick Johnson’s AZB post, which shows how the effective pivot point for aim compensation (the “squerve or squirve pivot point”) is different from the natural pivot point (the “squirt pivot point”) for the shaft.
Based on the diagram, to use pure FHE, you would first align the cue center-ball along the desired shot line, with your grip at the squerve pivot point. Then you would shift your bridge hand sideways (while keeping your grip hand fixed at the squerve pivot point) to place the tip for the desired amount of sidespin. Then you would stroke straight along this new alignment. This will correctly compensate for squirt and swerve and send the CB in the desired shot-line direction.
To use pure BHE, you would first align the cue center-ball along the desired shot line, with your bridge at the squerve pivot point. Then you would shift your grip hand sideways (while keeping the bridge position fixed at the squerve pivot point) to pivot the cue to the desired amount of sidespin. Then you would stroke straight along this new alignment. This will correctly compensate for squirt and swerve and send the CB in the desired shot-line direction. An alternative to a pre-stroke BHE pivot is to use a swoop stroke (with the pivot occurring during the stroke), which would still send the CB in the same direction (unless the swoop motion is really exaggerated).
For this particular shot, with the effective pivot point (“squerve pivot point”) as diagrammed, it might not be easy to do either of these. That’s where a combination of BHE and FHE becomes useful, as demonstrated in the video and articles on the BHE/FHE resource page.
An alternative to these approaches is to do what most pros and top players do: Just place the cue along the necessary direction, away from the desired shot line, to intuitively compensate for squirt and swerve, guided by countless hours of practice and successful experience, and then stroke straight to send the CB in the desired shot-line direction.