Recent content by nataddrho

What is grade-A? Reference?

This is excellent work!!

I like to generalize to say that your best performance comes from eyes locked onto “something” whether it is cue ball, object ball, or the cloth in between. As long as your eyes are not moving you can learn from it to make your own decisions. If your eyes are always moving around you will be...

Pool is unique like in golf in that you have two simultaneous targets. The tip position on the cue ball and then some time later the CB-OB collision. Because of your field of view and focal length differences, you can not “see” both targets. Golf is very obvious because your body is completely...

No, it is not possible.

Firmware Update Now Available 5/22/2026: Version 1.1 - Better cue impact detection that reduces the likelyhood of false triggers. - Improved cue straightness and steering detection for hard or fast shots. iOS: Use the DigiDFU app. A video tutorial can be found here. Android: Use the nRF...

I have Klematch P37, high quality rails with a standard profile (shown in the video). The DIN53512 standard is harmonized with ASTM D1054 and uses a standard sample to measure rebound with a precision pendulum machine like this one. I can estimate the immediate rebound by multiplying my...

I measured again during an 80 degree day with 50% humidity. The rail rebound / COR was 0.548, which is 6.8% higher then on a 47 degree day. This means that a perfect lag shot on the cold day will roll about 6 or 7 inches longer on the hot day, if the shot had the exact same amount of energy...

I learned stroke basics on a cheap $250 MDF table from Dicks, and yes it did warp and I threw it away after a year. I also learned jump shot basics even though it was MDF.

Their carbon fiber shafts are phenomenal. Market leader.

I don’t really think that this concept solves a problem that needs to be solved. People don’t have trouble telling which side of the pocket that they missed on. This is also a product that has been invented and reinvented over and over again for 50 years. It isn’t novel. So don’t sweat it.

The definition here of COR (COF was a typo) can only be defined as what is shown at 0:30s of HSV B.15 video mentioned above. If you really wanted to, you could measure the slope of the increasing spin after impact and use that as your cloth friction coefficient. Then do the math and back...

Though not the intended purpose of the DigiBall, Dr. Dave's recent post, which included a high speed video of a ball rebounding off of a rail, gave me the idea to try to measure it directly. Here is his video: Dr. Dave measured the incoming velocity and rebound velocity of the ball by...

Don’t write off FedEx completely. I have only had success with FedEx and DHL for international shipping. All other carriers were consistently a headache and many months of delays. Especially UPS. For intranational it is a bit different.

The idea is to fill the holes with retractable steel rods, that create divots to place the balls, and then go flush immediately after breaking. The problem is that the 90 degree sharp edges between the slate surface and hole inner diameter will wear out the cloth at those points, as you pointed...