The real reason the bat verbiage in the sanctioning bodies rule books started was because of one manufacturer, DeMarini. When Ray DeMarini introduced his double wall bat in the mid 90's to the slow-pitch masses, the performance was off the charts compared to other bats at the time (exception of titanium). The various sanctions outlawed titanium and double-wall shelled bats for use and DeMarini decided to take them to court. The courts sided with him because there was no measurable standard to define what performance was "too much". Bat Performance Factor or BPF became the industry standard for a couple of seasons after that with 1.2 becoming the highest allowable number in NSA & USSSA. The measurement was of a trampoline effect of a struck ball off the barrel. The ASA allowed for some reason 1.3 to be the highest standard for their events and some companies like TPS had the Outlaw (1.3 BPF) that was only approved for use in ASA events.
Eventually around early 2000, Miken put out a composite based shell that was quietly being used. Then they released the Ultra and the sanctions reacted by banning them. Miken took many of the original Ultras back and replaced them with Ultra II's, but that bat also was banned shortly after release. The ASA decided at that time to switch to a MPH standard which was 98 MPH. The ASA banned several bats on the market when they made that switch which happened to coincide with their Labor Day Nationals. If any of you have the ASA chart of non-approved equipment, most of the ones on there are from the banning they did around 2002.
What people started to see with the composites was the more broken in they got, the more those fibers "flexed" which increased the trampoline effect and was essentially defeating the initial BPF rating of the bat. Now many of the sanctions are testing bats out of the wrapper, after rolling, and after a predetermined amount of swings or breaking in period. There are also machines that can test compression on the barrel of the bats to determine if the bat has been "shaved" or hollowed out from the inside which is the biggest form of altering in the softball world these days, especially at the adult slow-pitch level. In fact adult slow-pitch is a literal zoo with accusations flying that close to 90% of the more avid, tournament caliber, types of players all have altered or shaved bats. If you hit a ball within 10 feet of the pitcher, it almost always sets off a war of the words with players then trying to retaliate by hitting the ball right at the opposing pitcher in return.
Sorry for the long wordy history lesson but this is one of my sweet spots as a former avid slow-pitch player and director back in the old days when the best team won, not the team with the best equipment.
I think it has more to do with legal issues. the sanctioning bodies instituted their bat limitations pertaining to performance because of mounting injuries, and they didnt want to be liable. Bat manufacturers either adhere to this or their bats are deemed illegal for use, which is death to a model bat. Bat manufacturers would love to make ultra hot "disposable" bats that need replaced every 3-4 months, theyd make tons more money. They do sort of make what youre saying with bats materials that break down quicker out of the wrapper, breaking in quicker. When you hear about a certain model thats hot as hell but has durability issues this is why.
