When damage is dealt to a unit from different angles a bonus damage multiplier is done depending on how surrounded it is, the maximum modifier is 150% damage, for dealing attacks from 180 degrees on a single target. For this reason always aim to place pyros on opposite sides of a com when assassinating it. It is also useful to constantly hit an armored target like a sumo or jugg with a flea from the opposite side, while attacking or right before a liche attack - allowing you take it down up to 50% faster.
What is this referring to ?
I have never heard of nor seen such bonus being applied before, nor can reproduce in neither of the BA versions. :/
Edit:
Nevermind, i always had thought that flanking bonuses were default disabled. It's indeed happening after more tests. :D
Thank you !