Here's an example of chance of winning batman:
i have 10 attack my opponent has 30 attack, so i would win 10 out of 40 times or 25% (10/10+30)
Sorry, to correct you (but bett correcting than someone wondering about your calculation) , but in a 20:60 situation, the 20 has 25% chance of winning, not 33%. You have to add in the 20 attack points to the "100% chance" (does not exist!) as well, as was done in AOD-NEKO's example.
20 attack versus 60 attack = 20/80 versus 60/80 = 0.25 versus 0.75 = 25% versus 75%
Humm... clans do interfer in battle results? Not the bonus, I mean if using some clan or some card against other clan or card would be more effective?