Summary: David Alciatore, PhD ("Dr. Dave") ILLUSTRATED PRINCIPLES
"Squirt Part IV: BHE, FHE, and pivot-length calibration"
Note: Supporting narrated video (NV) demonstrations, high-speed video (HSV) clips, and
technical proofs (TP) can be accessed and viewed online at billiards.colostate.edu. The
reference numbers used in the article help you locate the resources on the website. If you
have a slow or inconvenient Internet connection, you might want to view the resources
from a CD-ROM or DVD. See the website for details.
This is the fourth article in my series dealing with "squirt." So far, we have looked at basic
terminology, the physics behind squirt, some experimental results, and the effects of follow and
draw on squirt, swerve, and effective squirt. To refresh your memory, squirt, also called
deflection, refers to the angular change in the initial cue ball (CB) direction due to an off-center
hit. In other words, when you use English, the CB doesn't go where you are aiming because of
squirt. For more background information, see my August '07 article and refer to NV 4.13 and NV
A.17. When using English, it is also important to be aware of the effects of swerve (see NV 4.14
and NV 7.12) and throw (see NV 4.15, NV 4.16, NV A.21, and my August '06 through July '07
articles). Sometimes, the phrase "effective squirt" or the term "squerve" is used to refer to the
net effect of both squirt and swerve on the shift in the CB position at object ball (OB) impact (see
my August '07 article for more information). If you want to refer back to any of my past articles,
they are all available on my website (billiards.colostate.edu).