EVE General Discussion

This is more of a rant followed by some information. One of my pet peeves is when people do not understand the way math works related to ship resistances. They assume resistance numbers are added together, and anything less is the result of a stacking penalty. They also wrongly assuming diminishing returns. The simplest example is that 50% + 50% does not mean you have 100% making you invincible, or what about 60% + 60%??? Your ship recovers hit points from incoming fire? No.

If you reduce incoming damage by half (50% resist) and then reduce it by half again (another 50%), the total incoming damage is 25% of the original, or a 75% resistance. Another way to say this is that the ship can take 4 times the damage it could with 0% resist. That is simple enough to understand, but how do you calculate those numbers? How do you figure out T2 resists? Here is a simple explanation. This could be simplified into a complicated looking algebraic expression, but I am going to write this out in English in hopes more people can understand how it works.

First, instead of thinking about resistances, we need to think about incoming damage, the math is a lot easier that way. Just flip the number so a 25% resist is now 75% incoming damage (1.0 subtracted by resistance)
Base thermal shield resist is 20%, so 1.0 - 0.2 = 0.8

Then find the inverse of that by taking 1 divided by 0.8. Or just type 0.8 on a calculator and press the 1/x button (even simple calculators should have that button). The answer is 1.25, or the ability to absorb 1.25 times the damage we normally could.

Next let’s do it again and figure out the same number for a T2 Adaptive Invulnerability Field. 30% turns into 0.7, the inverse is about 1.43.

Now multiply the two numbers. 1.25 * 1.43 is about 1.79. That number still means the same thing; it would now take almost 2 times the incoming damage to deal the same base damage. To convert it back to an Eve resistance percentage, just take the inverse, and flip. So the inverse of 1.79 is 0.56, flip it to 44%, which is the number the Eve client would show. No stacking penalty because you only have one mod on the ship.

Now let’s say it is a Caldari T2 ship. No problem, we just need to add in the 75% resistance to thermal damage (75% for primary and 50% for secondary). The inverse is 4. 4 multiplied by the base 1.25 number is 5, the inverse is 0.2, which flipped gives you the base resist of 80%. Add the invul and you get 1.25 * 4 * 1.43 = 7.15 which inverted and flipped is the 86% resistance you expect.

Adding the invul to get form 80% to 86% might seem like it did not help us much on thermal. Wrong, it helped a HUGE amount. Going back to the inverted incoming damage number. A base Cerb can take 5x incoming thermal damage. Add the invul (which appears to only give an extra 6%) and now the same Cerb can absorb over 7x the incoming damage. Toss on a DCUII and you are at 8.4!!

So while going from 75% to 90% on a resist might only seem like a 15% improvement, it is actually going from 4x damage to 10x damage, a 250% improvement!

Thanks God (and Gripen) I have EFT.

That post contains the typical misleading information I was try to educate people against. It blurs the distinction between a stacking penalty and the asymptotic nature the numbers are calculated. Stacking penalties are real. The other is just a misperception.

Stacking penalties effect a module's effectiveness based on the number of similar mod effecting the same attribute.
In your example, you gave the correct stacking penalty values, but the math is ultamently wrong (or super confusing)



For module 2, 55% * 0.869 is 48%, not 21.51%. If you add 55% and 48% you get 103%, you see the problem?

Reread my post and you will understand how the math really works.

There is(/was?) a bug with deep space transports that allowed for over 100% resists. Due to the ship bonuses. Not sure if its been patched yet.

Screenie

Maybe you should re-read his post to understand how the math really works, because the numbers he provides are correct.

In fact, there is no misleading information in that post, so if you're trying to educate against it, you should probably stop. I'd also question the notion in the OP about thinking about it in terms of incoming damage “since the maths is easier”, when doing so means you have to add a bunch of unnecessary steps and start doing fractional divisions instead of a simple subtraction.

His maths is entirely correct — you just didn't get what he was doing.
If his maths is incorrect, then so is yours because (surprise!) it's the same maths. If you can't see this, you are in no position to “educate” anyone on the matter.

Yes you can.

He calculates how much each module adds to the total resist in absolute terms. He then adds these terms together to get the total resists percentage. It's a very simple method that demonstrates what happens every time you add an additional module.

Face-palming at this reply. Go get a calculator and punch in his formula, the numbers it returns will not match his answer.

Or maybe I am just silly and don't understand, then maybe you can explain how 21.51% was calculated using his formula?

How about YOU just type his formula into YOUR calculator. His math is absolutely correct and in my opinion the best way to calculate the resists, for me its a lot easier than all the inverting you do but i suppose thats just personal preference. Anyway before you tell ppl that someone's math is wrong you should actually check it out first... (make use of the brackets ;-) )


But to not lessen what you are trying to do with your thread. your math is also correct and might be the better way for others to calculate it, as I said which way someone uses is just personal preference.

My apologies, I did misread his formula and came to the wrong conclusion. It is doing the same thing mine is and both return the correct answer. I will transfer 10M ISK to both of your accounts when I get on tonight. GF