fouls

 Dr. Dave's answers to frequently-asked questions (FAQs),
mostly from the BD CCB and AZB discussion forums

maintained for the book: The Illustrated Principles of Pool and Billiards,
the DVD series: The Video Encyclopedia of Pool Shots,
and the monthly Billiards Digest "Illustrated Principles" instructional articles


For more information seeand Disc V of the Video Encyclopedia of Pool Shots


double hits

How can you tell if a shot is a double hit or not?

HSV B.6 - double hit detection and avoidance, NV B.2 - Mike Page's double hits, push shots, and frozen balls, and my September '09 BD article explain and illustrate everything fairly well. My HSV DVD also has a nice feature on this. Also, for many example calls along with explanations, see:

NV B.63 - Instruction for pool rules quiz (part 2: small gap between the CB and OB)

Clips HSV A.110-A.115 also show the effects of speed, cue stick elevation, and follow-through on double-hit avoidance for a chalk-width gap between the CB and OB. Unfortunately, clips A.110-A.112 and A.113-A.115 are from different viewpoints and were shot by different shooters with different amounts of follow-through, but the results are interesting nonetheless. Notice that the cue stick nudges the CB in mid air (i.e., the shot is a foul) in the 3rd (fast) stroke of A.112. This one is tough to call even with the high-speed camera.

The following videos show some interesting methods that can be used to avoid a double hit when there is only a small gap between the CB and OB:


first contact legal hit

How can you tell if one ball is hit before another for a close-call legal hit?

See my November '09 BD article and:

Also, for many example calls along with explanations, see:

NV B.63 - Instruction for pool rules quiz (part 5: determining which ball is hit first)


miscue

Is a miscue a foul if it results in multiple hits?

In the current rules, a miscue is a foul only if it is intentional.

HSV 2.1 shows a good example of a typical miscue. HSV A.13-A.20 and A.98-A.109 show many more examples under different conditions. With most miscues, the tip slides along the cue ball, and the tip, ferrule, and/or shaft make secondary contact with the cue ball. The secondary contacts might partially explain the slapping sound you hear with a miscue. Normally, multiple hits on the cue ball results in a foul; but in case of a miscue, the multiple hits are not considered a foul under the current rules (unless the miscue is judged as "intentional"). For more information, see my December '09 BD article and:

One case where a miscue should be called a foul is when secondary contact clearly affects the shot. Here's a good example where the miscue might not be "intentional," but it should be ruled as a foul, because secondary contact is obvious:

HSV B.28 - frozen-ball kiss, miscue, and push shots and fouls

Actually, an argument can be made that all miscues should be called as fouls. The current rules require a single, non-prolonged, forward-stroke hit of the tip on the cue ball. All miscues involve the tip sliding along the cue ball, and most miscues involve secondary contact with the tip, ferrule, and/or shaft. Maybe all miscues should be called as fouls, because they are a result of either player error or intentional, unsportsmanlike play. However, the current "intention" of the rules is that only intentional and blatantly obvious "secondary contact" should be considered a foul. The shot in HSV B.28 is an example. Another example is where you miscue on a follow shot, and you trap the CB under the cue ... this embarrassing and unintentional miscue should also be called a foul, because there is obvious "secondary contact."


"scoop" jump shot

Is a "scoop" jump shot a foul, even if there is no miscue or multiple hit?

Yes. Here is the pertinent WPA rule, from Section 8.13:

A scoop shot, in which the cue tip contacts the playing surface and the cue ball at the same time and this causes the cue ball to rise off the cloth, is treated like a miscue.

HSV B.2 shows and explains what happens with various types of illegal "scoop" jump shots. For more info, see my

Also, for many example calls along with explanations, see my August '09 BD article and:

NV B.63 - Instruction for pool rules quiz (part 6: miscellaneous fouls)