As a bat shaving expert I have an intimate knowledge of bat altering. A local park owner and I had a conversation about illegal bats being used in sanctioned play. He thought the only way to keep doctored bats out of play was by supplying the bats or compression testing every bat each day of play. I let him know there was a cheaper and easier way to do this. 4 fields with 3 bats each (and 3 backups) would cost over $2000. And the time spent checking bats every night for league would not work because of time constraints. Next is my idea for an even playing field.
Compression tester $850
1000 hologram security stickers $75-150
At the beginning of a league or tournament season you would compression test each bat that a player wants to be used in play. Upon the passing of their bat a hologram security sticker would be placed on the top of the barrel and on the end cap. The security stickers, when removed, cannot be placed back on the bat. The stickers destroy themselves when removed a second time. In theory this works like a charm but there are some factors to be looked at:
What if the sticker breaks or comes off during normal wear and tear?
That is an easy fix; a compression test and a new sticker. It will be important to get a sticker that adheres well to a surface.
What if a player gets a new bat during the season?
Same as above except you might want to charge a small fee for the test.
What if a player suspects a bat is out of tolerance on the other team?
Same as above except you might want to charge a fee (set a price that will not allow the protesting to get out of hand) for the test.
This method will not be full proof as a compression tester is not 100% accurate but this system will save park owners time and money while acting as a huge deterrent to illegal bat use. I would suggest a quick check of the bats by the umpire at the beginning of each game. The umpire would be looking at sticker integrity: cuts in the sticker near top of bat where cap meets the barrel (maybe by a razor blade) or signs of removal. As I said not all systems are full proof but this one will definitely help keep shaved bats off the playing field at half the cost and half the time.