Math calculations for FFXi

[Yekyaa]

Ok, I was playing around with Excel to make myself a spreadsheet.
I was working on Accuracy as a base and would add more stuff later.

Unfortunately, out of about 4 different sites I found, using the same stats, I get differing calculations on Accuracy and to-hit rate. Even using the calculations provided on a certain wiki, I still come up with a calculation that differs.

My main question goes out to the mathematicians that have already done the work, basically for a clarification. For purposes of proper calculation... and because I want to make sure I have it right:

Assume 269 skill no merits, single-handed weapon, using NQ Squid Sushi, +24 accuracy from equipment, 7 Dex from equipment (not counting sushi) and a base of 80 DEX (THF75/NIN)

200+69*0.9 = 262.1
80+7+6 = 93 / 2 = 46.5

262.1 + 46.5 + 24=332.6

332.6 + 15% Accuracy = 382.49

Given this info, I should either have an accuracy of 382, but that assumes the only time you rounddown or floor a value is at the end.

Now, here's the question. I know a lot of these should be rounded down to nearest decimal or floor'd to nearest integer somewhere.
For some reason I get results varying widely (from 377 Accuracy to 390) between all the websites I've visited regarding this calculation.

What's the accepted version? I find it hard to believe it could vary by 13pts unless the 15% is calculated earlier in the computation, which doesn't seem right.

Does anyone have any insight into the calculation itself?
Also, when is the proper time to Round Down (nearest decimal) or Floor (nearest integer)?

[Valyana]

You floor at each step, so 262 + 46 = 332 + 15% = 381.8 -> 381

[Yekyaa]

So, basically that means I'm doin' it right (on my spreadsheet I'm flooring everything), and 3/4 of the sites i visited were doing it wrong.

200+69*0.9 = 262.1 (floored) > 262
80+7+6 = 93 / 2 = 46.5 (floored) > 46

262 + 46 + 24 = 332

332 + 15% Accuracy (49.8) = 381.8 (floored) > 381 accuracy

[Redshift]

Let me save you some trouble. I already made a WAR xlxs.
WAR DC_1.4b.rar

[Masamune]

Hello

I did the accuracy calculations on my excel calc as well, with the base assumptions provided, and i found 381 same result as Valyana (strangely i used very few flooring if at all into my calculations).

On hit rate topic, i got a result of 82,00% hit rate on Gcoli lvl82 (329 evasion and 67 agi)
Is this right ?

[Baelwulf]

Should be about right assuming the formulas are correct. lv 82 G Colibri have a level corrected evasion of 367, 381-367=14

14/2=7 and 75+7 = 82.

[Masamune]

huh?! What is this "level correction for Mob's evasion" you talking about ?

i used standard Hit Rate equation :

IF((((0,75+((Player_Accuracy-Monster_Evasion)*0,005))+(((Player_Level-Monster_Level)*4)*0,005))>0,95);0,95;
IF((((0,75+((Player_Accuracy-Monster_Evasion)*0,005))+(((Player_Level-Monster_Level)*4)*0,005))<0,2);0,2;
((0,75+((Player_Accuracy-Monster_Evasion)*0,005))+(((Player_Level-Monster_Level)*4)*0,005))))
+Adjustement

= 82.00%

with (in example provided above) :
Player_Accuracy=381
Player_Level=75
Monster_Evasion=339 (my bad, mistake wasnot 329)
Monster_Level=82
Adjustement=0 : w/e number to make for any difference with hit rate reported by a parser.

i just don't understand the 367 Monster_Evasion you getting :S

[Baelwulf]

(PlayerLevel-MonsterLevel)*4 is the level correction factor, it's simply included in the formula you used.

to clarify:

Level Correction is a penalty you take for fighting monsters above your level, approximately 4 evasion for every 1 level of difference(either way). In the case of Greater Colibri, they have a base evasion of 339, but they are 7 levels higher than you, so they gain the equivalent of 28 evasion to total 367 level corrected evasion. This means that you need 367 accuracy to attain a 75% Hit Rate on the monster. In order to find your actual hit rate, you take your accuracy, subtract the monster's level corrected evasion from it, divide it by 2, and then add it to the 75%.

[Redshift]

You should be using this (from the spreadsheet I posted earlier);

=IF((0.75+0.005*(ACC-EVA)+0.02*IF(pLVL-mLVL>0, 0, pLVL-mLVL))>0.95,0.95, IF((0.75+0.005*(ACC-EVA)+0.02*IF(pLVL-mLVL>0, 0, pLVL-mLVL))>0.1, (0.75+0.005*(ACC-EVA)+0.02*IF(pLVL-mLVL>0, 0, pLVL-mLVL)), IF((0.75+0.005*(ACC-EVA)+0.02*IF(pLVL-mLVL>0, 0, pLVL-mLVL))>0, 0.1)))

ACC = your ACC
EVA = monster EVA
pLVL = your level
mLVL = monster level

[Masamune]

ok thank you for the clarification Baelwulf.

Redshift: its same equation "factorized" but thank you, for confirming we not using wrong equation As for yur Calc, i found it during my research @ January, 1stly used it for reference but lots of things are missing so made my own calc. Still a great job nonetheless.

[Baelwulf]

I always just did it stepwise, but then I've never used spreadsheets for this sort of thing.

Figure out contribution to accuracy from skill:
200 + ((skill-200)*.9) = acc contribution from skill

Figure out accuracy contribution from DEX:
1Handers: DEX/2
2Handers: 3DEX/4

Figure out your accuracy from gear

Add them together, you have a figure that is your base accuracy.

After that, you find out the mob's evasion(still not sure how they do this, just been going off statistics given). Then you multiply (TheirLevel-YourLevel) by 4, and add that to their evasion, and now you have the level corrected base evasion statistic for your target.

Subtract their evasion from your accuracy, and divide it by 2. Add this number to 75, and you supposedly have your hit rate.

Sidenote: The 2 Acc = 1% Hit Rate is a nice approximation, but I don't think it stands in all situations, so just take it with a grain of salt.

[Callisto]

I guess I'll post this here instead of making a new thread...

Were the newer cRatio/pDIF amounts/caps ever actually confirmed(mainly for 2-handers), or are people still going off of the values on otherwiki?

[Masamune]

During my research, i found 2 versions for handling new dmg results while equipped with a 2hands weapon (compared to old formulas) :
a) Redshift@KillingIfritWARforum is multiplying pDIFs by 1.05 (if i'm not mistaken)
b) Seedo@KillingIfritMNKforum raised cRatio cap @ 2.064 instead of 2, Crit pDIF mod @ 1.06 instead of 1, Max Crit pDIF cap @ 3.15 instead of 3. (and that for ANY weapon, not only 2handers)

The rest of the formulas are same as the old ones.

Personnally, i use version b), matches pretty well my parsed results for TPing (i didnot verified thoroughly for WSs yet).

[Callisto]

Yeah my own messing around had found something really close to B but I didn't have enough time to get the sample size to make any worthy conclusion, thanks a bunch.

[diemos]

Can anyone confirm these formulas vs. what FFXICalculator's results yield? (at work and too lazy for maths)

[Masamune]

@ Diemos: where is that calc ? mind posting a link plz ?

[diemos]

FFXI Calculator

[Masamune]

that calc doesnot do any dmg calculations at all, only found an accuracy field. Also, we dont see which formulas this calc use :/

[diemos]

Whoops coulda swore there was a damage calculator on there too. Nifty little app though.

[Redshift]

Yeah, I used old pDIF x 1.05 = new pDIF. There isn't much else to go on

ok thank you for the clarification Baelwulf.

Redshift: its same equation "factorized" but thank you, for confirming we not using wrong equation As for yur Calc, i found it during my research @ January, 1stly used it for reference but lots of things are missing so made my own calc. Still a great job nonetheless.

What things are missing? Always looking to add more.