25% vs How the hell?

[LzPrst]

I am really curious about something. How the heck does the combat promotions calculate?


Example.

My regular (non-promoted) crossbowman vs a regular pikemen gives the following odds:

Xbow vs Pike
6.00 vs 4.00

How in the name of all seven seas does this work?

My own calculations would give something like:
Xbow base strength 6 x .5 (+50% vs melee) = 9
Pike base strength 6

result: 9.00 vs 6.00

now, I do see a certain shall we call it possibility, namely that the advantage is the same i.e 3 vs 2. but I really don't get why the Pike gets it's strength reduced by 2. does the vs 25% / 50% add only to base strength? or rather, reduce the opponents base strength?

so for example.

if my Xbow has Combat II, giving it +20% strength for a total of 6.00 x 1.20 = 7.2, is that number by any way affected by the +50% vs melee? I guess what I'm asking is, do these effects stack. it seems to me that they don't...

Is this explained somewhere?

[LzPrst]

how about a big nice cup of search the forums noob!!

http://forums.civfanatics.com/showthread.php?t=137615

(I know, talking to myself, not good sign of mental health)

[LzPrst]

I'm still a bit unsure about certain details in that post. I'm not a mathematician...

am I right to understand that the unit specific bonuses only apply if the defender has a bonus? why does this have to be so damned difficult?

[LzPrst]

http://apolyton.net/forums/showthread.php?s=&threadid=140622

ok. a wee bit easier, but still... ouch, my head is aching!

[Solomwi]

All the attacker's bonuses except the combat promotion line are discounted from the defender, rather than applied directly to the attacker. First, they're applied to neutralize the defender's bonuses (so, if the pike was on forest, it would be 6 v. 6, since the x-bow's +50% would simply remove the pike's 50% defense bonus from terrain). Then, any remaining bonus is used to reduce the defender's base strength via the formula ES = BS/(1+X), where ES = effective strength, BS = base strength and X = remaining attacker bonus. Since, in your example, the pikeman had no bonuses and the x-bow had a 50% non-combat promotion bonus, the calculation is as follows:

ES = 6/(1+0.5) = 6/1.5 = 4.

The x-bow, since its only bonus was the +50% v. melee, remains at its base strength of 6. The ratio in this case is still 1.5, as you'd expect just from looking at the unit attributes.

EDIT: Sorry, I should have read past the first post.

[Theben]

LzPrst talking to himself