[Maths] DR, DI, Penetration and Defense
UPDATE: There was a fatal mistake with defense table and total effectiveness of Disturb/Dazzlement is actually 13-15%.
It’s been quite a while since penetration was modified so that it wouldn’t apply to defense anymore. After some time there was a question on how defense and defense reduction are effective now and I couldn’t give a satisfactory answer. Therefore, this time I’m going full out comparing similar effects of defense decrease, penetration power and damage increase.
TL;DR for all of you who dislike maths and formulas: ...just scroll to near bottom, just before the afterword.
##DR/DI
DR is short for Damage Reduction which is a visible in-game stat. It literally reduces the damage received by player. DI is Damage Increase effects like EBM, Ivy’s debuff or Elaine’s active. In terms of mechanics, they are one and the same with DI bearing negative numbers (i.e. EBM’s 20% DI = -20% DR). It is probably easier to visualise it as damage modifier (DM for short) which equals DM = 1 - DR. System only shows us DR after processing all DM effects.
For example, we have two DR effects of 30% and 20%. It means that we’d receive 70% of the damage and then and further 80% of that reduced damage, which means that after those two effects are applied, we’d receive only 70% × 80% = 56% of original damage. Which means, our final DR is 44% (using Kevin + Isillia).
Adding DI effect is analogical. For example, we have 30% DR and add 20% DI to it, it means first effect reduces our damage to 70% and second increases that damage of the decreased value by 20% to 120%, so we’d receive 70% × 120% = 84% or 16% of final DR.
Using more universal notation, we receive this formula:
effectiveDM = currentDM × newDM
(1 - effectiveDR) = (1 - currentDR) × (1 - newDR)
The damage modifier is not a visible stat, but DR is, therefore we get used to calculate DR instead since we can easily compare the result. For that sake, the above formula can be transformed into:
effectiveDR = 1 - (1 - currentDR) × (1 - newDR)
##Defense and Disturb/Dazzlement
We already know formula of Defense modifier:
DFM = 1 - DEF ÷ (DEF + 700) × 0.9
Instead let’s look at the practical side. First of all, let's take a look at defense, or more precisely at only defense debuffs which are Disturb and Dazzlement, both of which reduce defense value by 40%. Here’s how it affects the EE goalkeepers (assuming MSPU+160 with a defense stone):
| Player | DEF | Pos | Stone | DM | Dis | DisDM | Difference |
|---|---|---|---|---|---|---|---|
| Zibroi | 359 | 467 | 527 | 0,614 | 340 | 0,706 | 15,02% |
| Black Tortoise | 355 | 462 | 522 | 0,616 | 337 | 0,708 | 14,91% |
| Kei | 341 | 443 | 503 | 0,624 | 326 | 0,714 | 14,51% |
| King Jin | 340 | 442 | 502 | 0,624 | 325 | 0,715 | 14,48% |
| Isillia | 339 | 441 | 501 | 0,625 | 324 | 0,715 | 14,45% |
| Lucian | 332 | 432 | 492 | 0,629 | 319 | 0,718 | 14,25% |
| ZUXX Robin | 322 | 419 | 479 | 0,635 | 311 | 0,723 | 13,95% |
| Irre | 318 | 413 | 473 | 0,637 | 308 | 0,725 | 13,83% |
| Angela | 315 | 410 | 470 | 0,639 | 306 | 0,726 | 13,74% |
| Ronald | 297 | 386 | 446 | 0,650 | 292 | 0,735 | 13,18% |
| Average | 332 | 431 | 491 | 0,629 | 319 | 0,718 | 14,24% |
Pos = Position bonus, Stone = defense with stone bonus (60), Dis = Disturbed defense, DisDFM = Damage modifier of the disturbed defense.
First thing to observe it that modifier has increased by 15%-17% with Disturb/Dazzlement debuff increasing the damage proportionally. Second is that Lucian has almost perfectly average defense. And third... hey, where’s Raklet? Well, Raklet’s special because she has a defense buff that is always on and two defense stones. Other special cases include Raklet with Nerua’s buff, Kei with his own buff triggered on low HP and Eden/Freyja’s Oracle Will. And case where you average goalkeeper (Lucian) doesn’t wear a defense stone.
| Player | DEF | Pos | Buff | Buffed | Stone | DM | Dis | DisDM | Difference |
|---|---|---|---|---|---|---|---|---|---|
| Raklet | 324 | 421 | 30% | 548 | 668 | 0,561 | 499 | 0,625 | 11,54% |
| Raklet + Nerua | 324 | 421 | 50% | 632 | 752 | 0,534 | 583 | 0,591 | 10,67% |
| Never Die Kei | 341 | 443 | 40% | 621 | 681 | 0,556 | 503 | 0,624 | 12,09% |
| Oracle's Will Lucian | 332 | 432 | 25% | 540 | 600 | 0,585 | 427 | 0,659 | 12,70% |
| No stone Lucian | 332 | 432 | 0% | 432 | 432 | 0,657 | 259 | 0,757 | 15,26% |
| New Jin | 340 | 442 | 30% | 575 | 635 | 0,572 | 458 | 0,644 | 12,60% |
Buffs and debuffs counter each other, so there’s no surprise that you’d gain less damage against players with buffs.
On a side note, notice that Oracle’s Will reduces the modifier by roughly ~7% (0,629 -> 0,585 without Disturb), while a defense stone reduces it by ~4,3% (0,657 -> 0,629) considering your average Lucian.
Let’s also not forget, that Disturb reduces chance for coop defense. Probability is unknown, but when it happens, a 50% modifier becomes 33,(3)%, so basically you’d lose 33,(3)% damage if it procs, or 50% when defender is down, but another one comes to the rescue.
##Penetration vs. DI
Some time ago, I’ve already posted some examples of Pen vs. DI values and drew some simple conclusion. This time I’ll move a bit further. The problem with that it did not consider further sources of penetration power, which is pretty important for realism. After all, every source of DI reduces effectiveness of pen.
You may wonder why DI has diminishing return when combined with penetration power, so here’s an example. Assuming opponent has 70% DR and we deal base damage of 1000 with 40% penetration. Effective DR will be 0,7×(1-0,4/2)=56% thus giving us 440 end damage. If we add EBM to it, our 70% DR will become 1-(1-0,7)(1+0,2)=64% before being penetrated which in turn gives us effective DR of 0,64×(1-0,4/2)=51.2% leaving us with 488 damage. We can calculate that it is 488 / 440 - 1 = ~11% damage gained.
With that explained, let’s start from out damage factor:
DM = (1 - DR × (1 - pen ÷ 2))
First thing we need to consider is that there is a situation, when penetration power is nullified completely and that happens when DM exceeds 100% (a.k.a. negative DR). To know when the newly added DI effect would exceed that value, we need to solve this equation (penetration is applied after all DR/DI calculations, therefore it is not needed at this stage):
DM = (1 - DR) × (1 + DI) > 1
Which ends with this:
DR < DI ÷ (1 + DI)
For example, when using EBM (20% DI) we calculate threshold of 16,(6)% DR. That means that a 15% DR player will have negative DR after using EBM, but player with 18% will still have positive value, although barely.
Second condition is that total penetration power never exceeds 100%. Therefore, there is no difference in adding 20% of 30% to someone who already has 80% and there is no point in adding any point to someone who already has it maxed.
Done with the easy part, now’s the real hurdle. Question is when it is better to add some penetration power instead of DI effect. In the last topic, I’ve simply summarised it with pen being more effective on high DR opponent’s, while DI is is really useful against low DR ones. While it is true, that answer does not really satisfy me. Therefore, let’s get back to damage modifier, shall we?
DM = (1 - DR × (1 - pen ÷ 2))
Now, what happens if we were to add a new penetration effect (called newP)? Needless to say, total penetration can’t be more than 100%. It changes into:
DMP = 1 - currentDR × (1 - (pen + newP) ÷ 2)
This one’s tricky. What happens if we were to add another DI effect (let’s call it newDI)? Remember that you don’t simply add DR/DI, but use this to transmute the simple formula into a monster.
effectiveDR = 1 - (1 - currentDR) × (1 - newDR)
DMI = 1 - (1 - (1 - currentDR) × (1 + newDI)) × (1 - pen ÷ 2)
Good news is that it’s probably the last formula we need. Time to run some numbers.
##Def debuff vs. Pen vs. DI
Now the important question: what the hell does that even mean? The pinnacle of these formulas is to answer, in which situation, a pen buff would be better than additional DI and while at it, see if it’s better than Disturb. Purely for the sake of aesthetics, I posted some practical results of this gibberish in a separate post below, since it’s just a mass of tables.
After consulting with tables, you can see few things we already know: penetration power is very useful against high DR opponents, but useless against low ones, while DI is exactly opposite - reaches full effectiveness against low DR opponents while barely affects high DR ones. What we get to know is how slow/fast do they gain/lose effectiveness.
If we compare Disturb skill to them that is unrelated to penetration or DR and has stable damage modifier increase of 13-15% and compare to other skills, it is:
-
approximately equivalent of a 30% penetration (if we had below 70%) buff against around 55-60% DR
-
approximately equivalent of a 20% penetration (if we had below 80%) buff against around 70-80% DR
-
weaker than EBM when penetration is not involved, but unlike previous version of this file, it takes more effort for Disturb to outdo EBM (i.e. roughly 70-80% DR with 20% pen, 50-70% DR at 30% pen or 30-50% DR with 40% pen)
-
all than on top of decreasing chance of CO-OP defense
##Afterword
Well, that felt mundane, since probably rarely anyone would ever choose their units based on math and numbers alone. Treat it more like a curiosity
And lastly, I have fixed u/TheJediJew’s Defense, Damage Reduction and Penetration Tables to apply latest penetration nerf. You can find in a separate post below.
Here’s Jedi’s How to use those:
It is important to first select the table that closest matches the Penetration stat of the striker.
If you are only looking for the damage reduction of a goalkeeper then you can use the 0 penetration chart.
The values along the Horizontal axis (ie at the top) are Damage Reduction Percentages.
The values on the Vertical axis (ie down the left) are Defence scores.
The intersection point of the two values is the final damage modifier you can expect.
Note that I removed 0% DR colum due to character limit, but also because it is the same regardless of penetration power. That’s also the reason why “how to use” is separated from tables.
Posted May 3, 2016, 3:24 PM UTC · edited
##Pen vs. DI - How to use
It’s just a comparison of some values of pen and DI. Do not that it’s a comparison of effects that are meant for front totems and only those two effects even if player has different skills to boost damage or other benefits.
Also for Ravian and Sharr who have their own DI working regardless of totems should deduct that DI before looking up DR value. Tables only show what happens if you add an effect, not an effect that you’d use anyway.
For examples of DI values, I used EBM (20%), Elaine’s Active (30%), Elaine + EBM (56%), Black Ivy (15%) and Ivy + EBM (38%).
###Penetration power = 0%
###Penetration power = 20%
###Penetration power = 40%
###Penetration power = 60%
###Penetration power = 80%
###Penetration power = 100%