When they make the rubbers they are in a giant sheet that gets cut into the squares that are the size we buy. In the very center, there is one sheet. In the square around the center there are 8 sheets. In the very outer row there are 16 sheets. The theory is that the very center has the best rubber. The row surrounding the center is still pretty good but not as good. And the outside row, furthest from the center, the rubber is a little less good than the center and the inner row.
The outside row is commercial. The next row in is Provincial. And the one sheet at the very center is National.
They do this with Tenergy for the pros as well. So, with Tenergy, if you are buying it, you are getting the sheets from the very outside row. And it is still pretty good. The pros get the sheets from inside. I believe the Japanese players get the center sheets.
How different are they? With Hurricane, I believe, it is more important that you get the durometer (hardness) that you want and boost it well. They are a little different. Not so different that it really matters. A sheet of Commercial Hurricane that is 38-39 degrees that is boosted well is better than a National Hurricane that is 42-degrees and not boosted. All things being equal a National version that is 39 degrees and well boosted is a little better than a Commercial version that is 39 degrees and well boosted. Perhaps a little more than a little, but, not enough to matter to anyone, unless you are really playing at a very high level. I will keep the extra $80.00 (Commercial Hurricane=$20.00, National Hurricane=$100.00). The difference is nowhere near as much as the difference between Tenergy and Sriver. And the price difference between Commercial and National is a much bigger difference.
