And the answer is...
It seems this has reared it's head again and some players are a tad confused. Why do we tell them to divide by two after all those crazy calculation to find a 'final' number.
Well... it goes something like this - the display values in game are double the actual values... but not everything. Clear? Ya...
So to narrow it down a bit, let's focus on damage, deflection and armor(health). In the game displays, Armor is an actual value, damage and deflection however are doubled.
SO- you have a weapon that does 100 damage. A special that adds 50%, so you do 150 damage. The enemy has 100 deflection. 150-100 = 50 damage. Then you divide by 2. You are doing only 25 actual damage to that hull.
This is an important stat because it comes into use when trying to calculate TTK (Time To Kill) or HTK (Hits To Kill).
Before the refactor, since the numbers were sort of set for exceeding the deflection values, we knew the damage number. Many players were mis-calculating the amount of turrets they needed firing to eliminate an enemey. This was the reson.