fouls

• double hits
• first contact legal hit
• miscues
• "scoop" jump shot

double hits

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

HSV B.6 - double hit detection and avoidance explains and illustrates everything fairly well. My HSV DVD also has a nice feature on this.

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 betwee the CB and OB:

• NV B.49 - Using your knuckles to prevent a double hit and stop the cue ball, with Bob Jewett
• NV B.50 - Using your knuckles to prevent a double hit and get follow, with Bob Jewett
• NV B.51 - Using your natural forward stroke limit to prevent a double hit and get draw, with Bob Jewett
• NV B.52 - Using a fouette shot to prevent a double hit, with Bob Jewett

first contact legal hit

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

See:

• NV B.53 - How to determine which ball was hit first by watching the cue ball, with Bob Jewett
• NV B.54 - How to determine which ball was hit first by watching the object balls, with Bob Jewett

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:

• HSV B.36 - various miscues with double-hit rule interpretation

One case where a miscue should probably 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:

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.

"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.