Spell interruption down cap and Aquaveil Tests

[pchan]

Um, but wait... am I reading this wrong:



That's not right, the fact that skill prevents interruption is obvious to me at least -- if I go WHM/NIN to a crag and cast Ichi through a hit, it's interrupted every time. If I cast Reraise through a hit (or multiple), it's never interrupted.

It doesn't change the cap value at least. Wether you cast ustsusemi or stoneskin, you need exactly 77% from gear/merit + aquaveil to cap in both case (114 skill vs 256 skill).

If you cast stoneskin, are at 76% and get aquaveil you can be interrupted.

[Katoke]

ADIDAFFXI - Spell Interruption Rate down percentage is NOT capped!

This post pretty much covers a lot of whats said here.

[Dawin]

Stoneskin(76% + aquaveil) : 17 / 6
Stoneskin(77% + aquaveil) : 100/0

Even if we assume the maximum # of hits (9), this is very statistically improbable to match with your conclusions.

153 hits, 6 interruptions. Seems a lot more than 1%. Especially when you factor in that some of those interruptions are on the first 2 hits, and in reality it's closer to 100 hits.

[Seraph]

What ? I don't understand this part. There no statistical test needed to be done to see if you are -not- at cap. If you find just one interrupt it means you are below the cap and don't need to go further.

My original point was that I don't think you can dismiss Aquavail as being anything other than 25% so quickly.

Aquaveil could actually be 23%, or maybe 25%, or depending on how the gear percentages add up, it could possibly even be more than 25%, or less than 23%.

I think 25% is a very good estimate based on your test, but I wouldn't start tossing that value around as fact just yet.

[Dawin]

Stoneskin(76% + aquaveil) : 17 / 6

Utsusemi(76% + aquaveil) : 4/2

Utsusemi(101% + no aquaveil): 7/4

These all should be 99% (not the ratios, but per hit). When you factor in that stoneskin takes 2.5x as long to cast, it should have MANY more interruptions, but instead has far less (17/6 vs 11/6). This seems to be proof that skill level does matter.

Do you use any logic at all when making your conclusions?

[Dawin]

Also 1024 is not divisible by 102. Seems to indicate that the scale is not linear, and 1% x 10 will never be the same as 10% x1.

[pchan]

Even if we assume the maximum # of hits (9), this is very statistically improbable to match with your conclusions.

153 hits, 6 interruptions. Seems a lot more than 1%. Especially when you factor in that some of those interruptions are on the first 2 hits, and in reality it's closer to 100 hits.

Idk what you are saying honestly, I don't care about the practical % i get with 76%, The fact is I DO get some interrupt which is 100% fullproof that i'm not at cap.

[Dawin]

It seems like there is some sort of tier system that is dependent on skill level, as well as other factors (not sure which mob factors matter, i.e. level, damage, critical hit vs non critical hit, etc.). Would need many more samples to conclude this confidently.

[Suiram]

Also 1024 is not divisible by 102. Seems to indicate that the scale is not linear, and 1% x 10 will never be the same as 10% x1.

The point is more that just as with so many other stats in the game like haste and damage reduction, the values reflected in the item description aren't the exact values on the piece. A 10% piece is really 100/1024 or 25/256 or something. So it's more than you need 102% in item description spell interruption rate to achieve 100% true spell interruption rate.

Also it is interesting (although not entirely new) that interruption rate behaves peculiarly just below the cap, but I think the most important part of what pchan has shown is that you (some jobs anyway) can achieve a gear-only 100% spell interruption rate, and that there's not a seperate gear-cap/magic-cap thing going that caused earlier 100% spell interruption builds to fail. Whatever use that may actually be is up for future debate, I guess.

[Sifer]

This sounds more like crit hit rate than anything. crit hit rate is capped at 20% from stats but you can add 4% from merits and as much as you want from crit+ gear.

I'm guessing Skill+aquaveil cap at 25% but there is no cap on -interupt% from gear.

need more stoneskin/utsu tests w/o aquaviel.

skill+aqua having a cap would explain why these tests showed no difference between skill/no skill

[Seraph]

skill+aqua having a cap would explain why these tests showed no difference between skill/no skill

I had not even considered that. Aquaveil could actually be a variable % based on the skill of the spell type you are casting. That would really be a bitch to test and nail down if it was true too. :-/

[Spekkio]

it's worth noting that in my experience, a hit for any non-zero hp from a higher lvl target will generally interrupt a spell, while a hit for a lot more from a lower level target will usually not. in addition, what's been said about 75 skill vs 37 when casting utsu and interruptions is true from what i understand. a nin/war has a good shot at casting through getting hit while a war/nin has a very poor chance.

i would instead postulate that there's first a check to see if it wants to interrupt your spell based off lvl, skill, and maybe damage, then it tallies your spell interruption down gear and rolls a saving throw against it. if you pass the saving throw, the interruption prevention check succeeds despite the lvl/skill/etc roll failing. IE, in order to interrupt, you must both fail your first roll against your stats and a second roll against interruption % down. this is just a hypothesis, but it would tend to support what we've seen.

an easy way to test this would be to try to cast reraise with say 50% spell interruption gear on both whm and /whm with the main job in the latter case not possessing any healing magic skill. if skill has no impact on interruption, both the whm main and sub interruption against a finite number of tests should be fairly close. if there's a marked difference between the two, then we can conclude that there are likely two checks involved and not just a single one, or at the very least we can affirm that skill in some way does affect interruption rate.

[Suiram]

I have a 100% item-description spell interruption build which fails because it's not a true 100% build, likely for the reasons I brought up before. With that, blue magic spells have been interrupted, which casts doubt on your combined-skill-and-aquaviel idea, since A+ skill with 8/8 merits would surely be more than 2% if this were the case.

It seems more likely to me that you have some chance of interrupt based on skill x 1-spell interruption rate.

[Sifer]

I have a 100% item-description spell interruption build which fails because it's not a true 100% build, likely for the reasons I brought up before. With that, blue magic spells have been interrupted, which casts doubt on your combined-skill-and-aquaviel idea, since A+ skill with 8/8 merits would surely be more than 2% if this were the case.

It seems more likely to me that you have some chance of interrupt based on skill x 1-spell interruption rate.

was it on low level mobs?

[Suiram]

DC-T

[pchan]

Stoneskin(76% + aquaveil) : 17 / 6

Utsusemi(76% + aquaveil) : 4/2

Utsusemi(101% + no aquaveil): 7/4

These all should be 99% (not the ratios, but per hit). When you factor in that stoneskin takes 2.5x as long to cast, it should have MANY more interruptions, but instead has far less (17/6 vs 11/6). This seems to be proof that skill level does matter.

Do you use any logic at all when making your conclusions?

I think you are the one failing at logic. With 76% and aquaveil you do get interrupts on both utsusemi and aquaveil, it means that you are not at cap. With 77% and aquaveil you don't get interrupts on both spells.

What does this show ? Let's call x the % you get from 256 enhancing skill and y the % you get from 114 ninjustsu skill. Let's call z what you get from aquaveil.

No interrupt @ 77%/114 skill => 77+y+z >= cap
Interrupt @ 76%/114 skill => 76+y+z< cap

conclusion cap -77 <= y+z <cap -76

No interrupt @ 77%/256skill => 77+x+z >= cap
No interrupt @ 76%/256skill => 76+x+z<cap

conclusion : cap-77 <= x+z < cap-76

conclusion 2 : x+z and y+z lie both in the interval [cap-77,cap-76[ with has 1% length, this implie that the difference between both is < 1%, or :

(x+z)-(y+z)<1%
x-y<1%

142 skill difference gives strictly less than 1%, which means that skill doesn't affect your chance of being interrupted, at least when what you get from gear/spell is close to cap.

[Nermie]

Apologies if this has already been asked ... What are you casting Aquaveil in? Is it possible that Aquaveil has variable performance based on skill/modifier (similar to stoneskin with enhancing+MND)?

[Spekkio]

I think you are the one failing at logic. With 76% and aquaveil you do get interrupts on both utsusemi and aquaveil, it means that you are not at cap. With 77% and aquaveil you don't get interrupts on both spells.

What does this show ? Let's call x the % you get from 256 enhancing skill and y the % you get from 114 ninjustsu skill. Let's call z what you get from aquaveil.

No interrupt @ 77%/114 skill => 77+y+z >= cap
Interrupt @ 76%/114 skill => 76+y+z< cap

conclusion cap -77 <= y+z <cap -76

No interrupt @ 77%/256skill => 77+x+z >= cap
No interrupt @ 76%/256skill => 76+x+z<cap

conclusion : cap-77 <= x+z < cap-76

conclusion 2 : x+z and y+z lie both in the interval [cap-77,cap-76[ with has 1% length, this implie that the difference between both is < 1%, or :

(x+z)-(y+z)<1%
x-y<1%

142 skill difference gives strictly less than 1%, which means that skill doesn't affect your chance of being interrupted, at least when what you get from gear/spell is close to cap.

i think the issue is that you're postulating that the effects of lvl correction and skill are additive to -interruption. suriam and i are both postulating that -interruption is a multiplier to the effect, not additive. as such, even if there were a 50% higher chance of being interrupted w/ 142 less skill, with 99% -interrupt gear it would only register as a half% swing, not remotely enough to be seen in the data set. i'm not saying you're wrong, i'm merely suggesting another explanation for your data set.

what your data set fairly clearly shows though, is that the %'s are not stored in base 10, but in fractions of most likely 256 and that by capping that value independent of any other environmental factors outside of stun, silence, petrify, dead, etc is sufficient to generate an immunity to interruption.

[Sifer]

DC-T

Thinking about it again, Im sure I get lower interupt rates on level 1 mobs than 75%. Pretty sure i get interupted alot on DCs tho (A- skill on drk)

[Suiram]

i think the issue is that you're postulating that the effects of lvl correction and skill are additive to -interruption. suriam and i are both postulating that -interruption is a multiplier to the effect, not additive.

I don't think pchan disagrees here. Or else you and I disagree and I wasn't clear. What I'm saying (and what I think you're saying and pchan is saying) is that it seems most likely to me that the way it works is (chance to interrupt based on magic skill vs. enemy's relevant attributes/skills/levels) * (1 - (% interruption rate from gear + % interruption rate from aquaveil)) = (total interruption chance). Some other people were saying it was maybe additive and I was saying I doubt that. Pchan seems to be arguing with the people who doubt that Aquaveil is 25% (and I'm personally comfortable with saying it's 25% for now given what we have and what we could work with, as well).