A Statistical analysis of Charm Duration

[charleski]

Originally Posted by bcbrown [You must be logged in to view images. Log in or Register.]

Since every tick is an independent trial, when parsing the log couldn't you track the log entry for tash wearing off and group subsequent trials separately from tash-active trials?

That is certainly possible. I'll admit that I haven't really got round to working on the problem properly. This is partially because, as I mentioned, you definitely do want to keep mob MR low in order to handle the charm breaks smoothly. But this is something to keep in mind for future study.

The test comparing durations for the orc pawn versus the EJ skeleton is interesting. I would expect that a 46-level difference would completely saturate any level-dependent effect, but a 10-12 level difference I would have expected to be small enough to show an impact if there was one. I'm happy to volunteer two hours supporting further testing with either a 60 druid or 55 cleric.

One possibility that occurred to me is that level difference is factored in an exponential manner, such that small level differences have an appreciable effect, but beyond 10 levels or so it has shrunk to a vanishingly small level.

If you're happy spending several hours doing nothing other than staring at a mob waiting for it to break, drop Feressa a tell in the game. But it is pretty boring [You must be logged in to view images. Log in or Register.]

[shovelquest]

Originally Posted by charleski [You must be logged in to view images. Log in or Register.]

The fact is, however, that you can expect to see a charm lasting over ten minutes at least once in the course of a night. I don't know if there's a hard limit in the code, but obviously very long charms are quite rare given the exponential distribution.

But that same distribution, with actual classic charm durations would mean you should only see a charm last over FOUR minuets at least once in the night.

[Salaryman]

RED99

Its 50/50, either it breaks or it doesnt.

RED99

[DeathsSilkyMist]

Originally Posted by charleski [You must be logged in to view images. Log in or Register.]

Maybe I wasn't clear enough in my first post. Average charm duration is completely meaningless.

This is incorrect. Looking at the EQEMU source code (The server code that P99 uses as it's base), it has the following comment for charm duration:

https://github.com/EQEmu/Server/blob...ells.cpp#L5542

//Average charm duration agianst mobs with 0% chance to resist on LIVE is ~ 68 ticks.

I doubt the programmers who coded P99 are wrong about how the results of their code work, and if it can be averaged or not.

The reason why charm duration is still a normal distribition is because each tick simply rolls a dice to see if you succeed or fail the charm resist check. The dice roll success threshold is adjusted based on level difference and MR.

The reason why you see the highest charm rate in the first 30 seconds is probably related to the EQEMU comment for charisma checks. It says Charisma is used for the initial resist check only.

Here is the comment in the EQEMU code for charisma checks on spell resists:

https://github.com/EQEmu/Server/blob...ells.cpp#L5469

/*
Charisma ONLY effects the initial resist check when charm is cast with 10 CHA = -1 Resist mod up to 255 CHA (min ~ 75 cha)
Charisma less than ~ 75 gives a postive modifier to resist checks at approximate ratio of -10 CHA = +6 Resist.
Mez spells do same initial resist check as a above.
Lull spells only check charisma if inital cast is resisted to see if mob will aggro, same modifier/cap as above.
Charisma DOES NOT extend charm durations.
Fear resist chance is given a -20 resist modifier if CHA is < 100, from 100-255 it progressively reduces the negative mod to 0.
Fears verse undead DO NOT apply a charisma modifer. (Note: unknown Base1 values defined in undead fears do not effect duration).
*/

Now P99 does have changes to the EQEMU code that are not in the github repo, so it's certainly possible things work a bit differently on P99. But it's good to see the thought process of the developers who worked on the code.

I did a weapon DPS calculator using the EQEMU codebase recently:

https://www.project1999.com/forums/s...0&postcount=41

And the results closely match P99 parses. This shows that the EQEMU code can still closely resemble the P99 code. They don't need to completely rework the EQEMU code for P99. I'd be willing to wager most of the P99 code changes in the P99 codebase are related to adjusting code/variables based on what patch the server is on. They probably don't have sweeping changes to the EQEMU base code.

[DeathsSilkyMist]

On an off topic note, the charisma check comment:

/*
Charisma ONLY effects the initial resist check when charm is cast with 10 CHA = -1 Resist mod up to 255 CHA (min ~ 75 cha)
Charisma less than ~ 75 gives a postive modifier to resist checks at approximate ratio of -10 CHA = +6 Resist.
Mez spells do same initial resist check as a above.
Lull spells only check charisma if inital cast is resisted to see if mob will aggro, same modifier/cap as above.
Charisma DOES NOT extend charm durations.
Fear resist chance is given a -20 resist modifier if CHA is < 100, from 100-255 it progressively reduces the negative mod to 0.
Fears verse undead DO NOT apply a charisma modifer. (Note: unknown Base1 values defined in undead fears do not effect duration).
*/

Does give some insight into why Necromancers have minus Charisma on their gear. I didn't know that fear ever had a charisma check. It makes sense, the lower your CHA, the scarier you probably look. Don't know if this CHA check for fear is on P99, but it is interesting.

If this is on P99, it means Enchanters have a resist penatly when using Fear with their CHA gear on.

[kjs86z2]

Originally Posted by charleski [You must be logged in to view images. Log in or Register.]

Average charm duration is completely meaningless.

ummm...no?

[Goregasmic]

Originally Posted by charleski [You must be logged in to view images. Log in or Register.]

Maybe I wasn't clear enough in my first post. Average charm duration is completely meaningless. The concept of a mean only works for normally-distributed data. A lot of data does come from a normally-distributed population, but in this case that simply isn't true. For exponential data like this you can use the median instead, but that has very limited utility and generally doesn't allow the application of statistical tests. You really need to perform a deeper analysis of the data and extract an estimate of the core underlying probability.

What I meant is when you're in your mid 50s and you charm a low to mid 40 mobs, it will usually last a couple minutes on most charms if you remove the outliars. With similar conditions, his attempts on the ilis shaman rarely broke the 60 seconds mark. This suggests mob level plays a major role in charm duration.

Originally Posted by charleski [You must be logged in to view images. Log in or Register.]

As an aside, ironically I did notice a resist on the initial cast of Cajoling Whispers last night, so it can happen. It does seem very rare though, and I have to wonder if this shares the same 98% success rate that's applied to charm break rolls.

Since my mid 40s I don't think I've ever had an initial cast resist on any charm. Only resists I had was landing a lower charm on a mob that was too high. That being said I almost always mez + tash + charm. Considering a ton of charms break before 30 ticks I don't think it is the same formula for charm landing because I'm at like 100% success rate.

I've been thinking about this lately and in my 50s I think I got a single color slant resist and maybe also one mesmerization resist? Not 100% sure, I could swear it happened but it is VERY rare if even possible and those mobs aren't always tashed. But now that I think of it, it also has been a LONG time since I got a nuke or slow resist. Unless I get a crit fail on lull I usually tash everything to make root more stable and lessen the odds of getting a simultaneous root+charm break. I feel like except for charm, the last tash you get in your mid 50s really makes almost everything land for most of the exp trash but then again you're fighting mobs 10-17 levels below you so it is hard to know what does what.

Lull on the other hand... been getting fewer crit resists as levels go up but regular resists are still quite common.

[Goregasmic]

Originally Posted by DeathsSilkyMist [You must be logged in to view images. Log in or Register.]

/*
Charisma ONLY effects the initial resist check when charm is cast with 10 CHA = -1 Resist mod up to 255 CHA (min ~ 75 cha)
Charisma less than ~ 75 gives a postive modifier to resist checks at approximate ratio of -10 CHA = +6 Resist.
Mez spells do same initial resist check as a above.
Lull spells only check charisma if inital cast is resisted to see if mob will aggro, same modifier/cap as above.
Charisma DOES NOT extend charm durations.
Fear resist chance is given a -20 resist modifier if CHA is < 100, from 100-255 it progressively reduces the negative mod to 0.
Fears verse undead DO NOT apply a charisma modifer. (Note: unknown Base1 values defined in undead fears do not effect duration).
*/

So if I understand correctly, above 75cha you get -1 resist check every 10cha up to 255, so considering diminishing returns probably like -15resist at 255?

(200-75)/10=12.5
(55/10)/2= 2.75

The last 55cha would be about -2.5 resist, which isn't much but I guess it matters when it is the difference between killing a named or getting harm touched by an entire room.

As for fear as an enchanter, I bought them all and I never casted one. Can't comment on that one. I can see situations where it would be useful but those are some edge cases.

[PatChapp]

Would be interesting to compare necro charm vs enchanter
Say 50 charms of the same mob each and compare durations. Maybe do it untashed to keep the mr equal.

[bcbrown]

You can tell by looking at a graph of a normal distribution or an exponential distribution what better fits your data. A normal distribution looks like the familiar bell curve everyone knows. An exponential distribution has a peak at the minimum value and swoops down in a curve till there's fewer and fewer at higher values. The two graphs are attached. It's clear that when looking at the provided histogram of charm duration, the exponential distribution is a better fit to the data.

Looking at these graphs also shows why the average is meaningless for data that looks like the second graph. The average is going to be a vertical line placed on the graph such that the area under the curve on the left half is the same as the right half. For a normal distribution it's obviously going to be at the top peak of the bell curve, and that's exactly why it's useful there: you know that most of the data is going to be close to the average value, and the variance tells you exactly how close.

Looking at the exponential graph also demonstrates why the average isn't very useful in this case. You can place a line that marks the average, but it's not going to tell you anything useful. Assuming you're dealing with a system that has a set chance to break charm every tick, you want to find what that set chance is, and what if anything modifies that chance. The average value doesn't help with that.

charleski, in your results you report a "p charm success per tick" value. How is this calculated? Is it the same as p-hat (charm breaks / total ticks)? Given your discussion of MR and the challenges with handling tash wearing off, were all the data collected without using tash? Are you calculating total ticks for each charm as something like total charm duration in seconds / 6, rounded down? I'm sure I can answer these questions by looking at the code, but haven't had a chance to do that yet.