There are a few differences. The volcano variants don't have fixed places for the volcanoes. They appear random in the middle in a symmetrical way.

Another difference is that at IYT you can 'shuffle' two unseen pieces around so your opponent doesn't know which of the two pieces is the unseen piece who just caught his 4. You understand what I mean? Here at BrainKing on the right side of the gameboard there is a notation of every move, so you can tell exactly which piece moved where.

The tournaments work very different as well. The good thing is we can design them ourselves and the results are automatically registered and neatly listed: