Wardad:
This is the math you look for. Yesterday I have spent two hours inventing this. Just check what all those abbreviations mean.
((TH sqared with AAW)!)/(100 sqared with AAW!))*AWW +CAM -CDM + E
For your 50% chance:
s=sqared
50%s(2weapons)!
---------------
100%s(2weapons)!
50s(2) 50s(1)
------ + --------- = 0.75
100s(2) 100(1)
