heh, this sort of reminds me when people wanted to play pokemon or yugioh online. The only times I ever bothered was when I did it with my friend who had a camera so we could both see our cards. Everry other time , people got lazy / quit, or just out right faked/cheated or lied about what cards they had. I found it quickly pointless after that. But , ahhh... good luck with this.
There is an actual program for playing card games online and it might be possible to make it work for bakugan. It was called Apprentice. We played yugioh, magic, pokemon, almost any card game could be played against others. Basically it is a database of cards and you play them and are able to randomly roll die and other things needed to play a game. would just need to come up with a way to randomly roll a bakugan with different results like maybe like 45% land on opponent card, 30% land on your card and 30% miss completely or something. basically just a random generator.
Ahhh yes , Apprentice was good when it was suported , I couldnt get it to work lately to insall.but for rolling the ball, you could use dice to see if they roll onto your card, there card, or no card, like you sugested. Sorry to derail this topic. 