Thanks for the answer, but what about the bad taste of being beaten? sometimes they have attacked me and I won but most of the time they attack me and win so I wanted to know some configuration so that it is not so easy to be beaten.
I understand, but you will have to realize that these guys spend huge loads of money on card upgrades.
(I can tell, I have sold tons of cards to them.)
So unless you want to spend a load of money on cards as well, there's just no way you could beat an experienced attacker.