How long is the tip in contact with the cue ball?

Clips HSV A.77-A.81 and A.147-A.151 show close-ups of cue tip impact for various hardness tips and various speeds. The Jacksonville Project, also did some measurements of tip contact time. Here are newer videos showing how contact time varies with cue speed and acceleration:

Here is a summary of the results of these videos:

  • most contact times (i.e., for most tips and most speeds) are in the millisecond range (about 0.001-0.002 sec).
  • a soft tip at slow speed has a longer contact time (as high as 0.002-0.003 sec), but still extremely small.
  • a very hard tip (e.g., phenolic) at fast speed has a shorter contact time (as low as 0.0008 sec).
  • tip contact time increases slightly with slower speeds and decreases slightly with faster speeds, but not by much (still in the millisecond range).
  • tip contact time increases slightly with acceleration at impact and decreases slightly for deceleration at impact, but not by much (still in the millisecond range).
  • what the player does with the cue during tip contact has no effect on the shot.
  • chalk does not stay on tips (especially hard tips) very well at impact (see the blue clouds that separate from the tips in the videos).

Some people think that what they do with their grip hand or follow through can have a big effect on the tip contact time, but this is not the case (i.e., it is not possible to get a significant effect). For more info, see: effects of light vs. tight grip. Also, some people think a softer tip, which has a slightly longer contact time, can create more CB “reaction.” This is not the case (see cue tip hardness effects).

Typical changes in cue tip contact time (with shot speed and tip hardness) are not really important. With a longer time, the peak force is smaller over the longer contact time. However, the cue ball speed and spin will still be the same, assuming the tips being compared have the same hit efficiency. Although, a harder tip usually has slightly better hit efficiency and a shorter contact time (see cue tip hardness effects), so the CB might have slightly more speed (with a given stroke) with a harder tip for a given cue mass and speed. And with more speed, less spin will be lost on the way to the OB or cushion, giving the impression that the hit created more spin.

With an increase in tip contact time, the effective tip offset will be slightly greater (because the tip will rotate out with the CB during contact), but this will also result in more squirt, which will diminish the effectiveness of the slightly larger tip offset. For more info, see cue tip hardness effects and getting more spin with an LD shaft. Also, close to the miscue limit, the longer contact time can be a problem (making a miscue more possible). For more info, see the “Can a softer tip put more spin on the ball?” section here: cue tip hardness effects.

Some people think cue acceleration at impact with the CB has an important effect on cue tip contact time, but this is not the case. For more info, see stroke acceleration.

For more info and resources on related topics, see:

Over what distance is the cue tip in contact with the cue ball on a typical shot?

The contact distance is much smaller than most people think. For example, with a break shot with a very hard tip, a typical contact distance (per TP B.20) is only about 1/10 inch (3 mm). With softer tips, the contact time and distance is longer. With slower speed shots, the contact distance is shorter.

Why is contact time shorter with fast speed shots? Doesn’t the tip compress more with more force?

A faster shot does create larger forces at the tip that compress the tip more, but the larger forces also accelerate the CB faster, allowing it to separate from the tip in less time.

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