Think about it this way as well. On the Hybrid where the company (any company) is combining either a solid and a pearl or 2 different solids or 2 different pearls or whatever, what if in batch one the cover mix was 1 part solid 1 part pearl, but in a subsequent batch, someone messed up and put 1 part solid 2 parts pearl. The 2nd batch will have more pearl than the first batch, thus a difference.
Remember a few years back when Brunswick messed up on the Sidewinders. People bought some of the initial batches and loved the reaction and a few subsequent batches were nowhere close. Come to find out, Brunswick failed to add the particle to the mix in some of the subsequent batches, so there were normal Sidewinders that had the expected particle in the cover, and some that were pure resin/no particle added. Obviously a difference in the amount of friction the cover will create.
Plus, if one batch is poured in June and another in December, you have atmospeheric differences. More humidity/more cold could cause the amount of moisture in the air to have a difference in the ball cure time which will affect the cover, plus if any moisture makes it into the covers from the humidity in the summer, I bet you will see a difference there as well. Using Brunswick again, when the company first started Reynosa, there was a learning curve because of the amount of humidity in Mexico versus Michigan. Brunswick had to make adjustments based upon what they saw compared to the old plant.
Plus, another difference could be the casting machines used. Plants are huge. One batch might have been run on casting machines 1, 2 and 3, where as a subsequent batch could have been on 4, 5 and 6. Different machines have differences.
How about what ball was poured prior to the ball being poured now? The reason why the new Black Hammer costs so much is because the cover is pure urethane and Ebonite stops production, cleans the lines and machines before running a batch so no resin or other material makes its way into the coverstock batch for the new Black Hammer to ensure it is pure. If a company does not clean it, and lets say Storm runs a ball with the NRG cover and behind it runs a ball that does not have the NRG cover, if Storm doesn't clean the lines good enough or whatever, the ball may have some slight differences based on the previously poured ball.
Right now I am LOVING my Optimus Solid from Storm. Best Storm ball I have had personally in many years, for me. Box said mine were poured in May 2015. I bet if I bought another one and it was a fresh pour, say November/December, because of the weather difference plus the possible difference in casting machine used and whatever was poured in front of the Optimus Solid compared to what was poured prior to the Optimus Solid in May, I bet I will see a difference between my old ones and new one. Only way to tell for sure would be to have one from May undrilled and one from the new run undrilled with similar specs, drill them the same, and see what happens.
This is why literally, to get the same ball, you need to get one from the same batch.
