this was an amazing and very scientific series. Thank you!

I love that you guys are trying the cientific way. It is a pitty the results were only valid to that set of rubbers. The idea of the scientific method is to create general statments but it is better to leave it at that as inconclusive then try to force results. I'll give some tips on how to improve the method. As you noticed you had too many variables between the two, topsheet tacky vs grippy, sponge hardness, sponge thickness and rubber collor, first step is to isolate one variable. That step is crucial to create general statments. The best rubber for experienced players are horrible for beginners, you shouldn't mix the two type of observers in the same group. Chinese and european rubbers play completely diferent, advanced players with experience in only one style should only evaluate rubbers of that style. Calling a rubber red draws more atention to it and sounds more agressive then yellow, to avoid all preconcepts calling them "A" and "B" would be better. To avoid one observer influencing the other they should not talk to each other before writting down their answers. To avoid observers choosing the best rubber at random a second set of equal rubber could be added or a couple more advanced players. Probably sponge thickness affects hard sponge tacky rubbers in a different way then medium sponge grippy rubbers. It is expected thicker sponge would create more spin in chinese rubbers and more speed in european ones.

Great stuff guys. Fantastic over and series. Many Thanks.

Just wow, very, very interesting! Thanks.

Yay you start to upload more videos

Well, great series, but would be even better if you did it again with two rubbers ONLY different in thickness, not hardness as well. I also think, that japanese and german rubbers propably have a better quality control and therefore are better suit for testing.

Great job. Subscribing just for your hard work.

I am uncertain of the quality of that brand of rubbers. Ive never used them and the names are not too familiar. But i would question whether quality makes large differences. Id even think to compare atleast three of the same rubbers. I think it is absolutely necessary to ensure same hardness for the rubbers of different sponge thicknesses if you could.

Very intresting video. I agree sponge hardness the same would have been better test. It seems the thicker sponge had a higher throw trajectory or was it the hardness that created it. Thanks for a great study.

Also, you need to think of a rubber as having two "speeds". One normal (speed) and one tangential(spin) to the paddle. A little trig can provide the effective speed for any impact angle. An experienced player will tend to close the paddle more and will therefore be more influenced by the tangential coefficient of restitution. A flat hitter will only care about the normal coefficient of restitution. It is easy to see why there are two different opinions about the speed of the rubber.

The best thing to do is to try your friends bats and see what works for you. My story is that I got a blade that I thought was fast and stiff turned out to be controlled and soft in terms of stiffness. The backhand rubber I used was from trying my friends bat and the forehand was based on speed according to the manufacturer. It has taken me about a month and half and originally I didn't like the set up of what I had bought. I changed the forehand and backhand rubbers and yesterday at the club...

This is why I spend a little more money on my equipment now - the variation is too much - even between the exact same rubbers. While I could be wrong, I hope that the more expensive rubbers will have better QC and thus I won't need to change my game as much per new sheet. So there you go, consistency in many ways is more important than all of the other numbers on a rubber.

I want to see the results of this procedure but both red and yellow are 2.0

Wow... So the two sheets had different tackiness, sponge hardness and thickness.. Shame you didn't make sure at the beginning it was only the thickness that was different. I love your approach and method anyway! It should be repeated! A lot to be learned, thank you very much and well done.

A thicker sponge may feel softer even it is made of slightly harder material. The way companies rate rubbers hardness is not very useful anyway. I can't plug a degree of hardness into a formula so that it has any meaning. Rubber hardness should be measured by pressure to compress to a certain percentage of thickness. That number can be used for calculations. It would be better to think in terms of a spring constant.

Hey man, it really doesn't help at all. You say, "in some cases 2.0 is better in some cases 2.2 is better". That's like a general statement, "it may rain tomorrow, it may not". Sorry, but I expected a conclusive answer. So either your tests failed to determine that or you should accept that there is literally no way for a player to determine what rubber would suit them unless they try both. But then we know about this before this test. So what's new that you did?