How to Prevent Stacking

This is actually very very easy.

All you have to do is to ask your opponent to shuffle your deck parallel to the table instead of doing the cascade/sideway shuffle (which is how people stack)

Also, if they believe you have been putting cards together you can just tell them "ok just table shuffle my deck", and make sure you dont try to foil stack it. The moment they do some random arrangement, call a judge (obviously they are trying to foil stack or do something retarded.

or you could request them to just cut the deck as many times as they want.

In the OCG, from what i know, in Malaysia last year, you are allowed to request such a thing.

However, in the TCG, in my knowledge, you cannot, because apparently: "your opponent has the right to shuffle however he wants". I am not too sure about this policy but it was stated by a couple of opponents in a regionals/ nationals when i requested them to do so .

Maybe it is only in australia, but not in other places (idk), but i think TCG Konami should just apply that policy, as letting your opponent perform a sideway shuffle is just stacking or potential "looking at bottom of deck to know your deck and open 1st turn shock master and call monsters yes i am still salty"

The end.