Back to the Basics II

Back by unpopular demand, Khaki prepares to explain more game mechanics straight from Mamook. For those of you who are not math savvy in the slightest, run fast! Yes, that means you, Snippy; dive under that box now! Ahem. Now then, today's post explains how one could theoretically calculate one's hit rate. In other words, field tests are not used to determine this value directly.

Recall that you should not place an emphasis on Accuracy if it is already capped on a given opponent, but how could you tell if your Accuracy was capped to begin with? One method would be to to use a parser, but there happens to be another way for those who do not get merit invites often. It turns out, you can calculate your Accuracy by checking your opponent and doing some math. To determine your Hit Rate (%), you will need to determine your Accuracy and your foe's Evasion first. The following rules (taken straight from FFXIclopedia) are used to do just that:

1. When your Accuracy equals your enemy's Evasion, you have a 75% Hit Rate.
2. For every one point of Accuracy added/subtracted above, your Hit Rate is expected to change by ±0.5%.
3. When fighting a higher-level monster, you suffer a four Accuracy penalty for every level that monster is above you.
4. When fighting a lower-level monster, you receive a four Accuracy bonus for every level that monster is below you. 

If you put everything together and convert every two points of Accuracy to +1% Hit Rate, you get:

Estimated Hit Rate (%) = 75 + [ ( Your Accuracy - Monster's Evasion ) ] / 2 + [ ( Your Level - Monster's Level ) * 4 / 2 ]

Estimated Hit Rate (%) = 75 + [ ( Your Accuracy - Monster's Evasion ) ] / 2 + [ ( Your Level - Monster's Level ) * 2 ]

Okay, that is good to know. Now how do I find my enemy's Evasion, Khaki?

Glad you asked, Liabelle. It turns out we cannot find this value directly either, but when you check a monster, it returns one of three values: low, moderate, or high Evasion. Again, there are rules (from FFXIclopedia) for using check as well:

1. If a monster checks as high Evasion, you have a less than 60% chance to hit it. Mathematically, your accuracy < your enemy's Evasion - 30 
2. If a monster checks as low Evasion, you have at least an 80% chance to hit it. Mathematically, your accuracy ≥ your enemy's Evasion + 10

If you get no message (moderate Evasion), your Hit Rate is somewhere between the two values.

The following image is used to determine my Hit Rate (%) on a Mamool Ja Lurker (THF):














Since my Accuracy set had more Accuracy to work with, I decided to calculate my Hit Rate (%) using that. The idea was to play around with my Accuracy until the monster changed to high or low Evasion (ideally, the latter). If I could trigger one of the two situations, I could then calculate my Hit Rate using the inequalities above.















It turns out that the VT Lurker (THF) had high Evasion even with all my Accuracy gear equipped, so I decided to use a plate of Sole Sushi to boost my Accuracy further. Ideally, I wanted to just hit high Evasion, and to my good fortune, the Lurker dropped from high to moderate Evasion upon equipping +28 Accuracy.















To confirm that you just crossed a threshold, add or subtract 1 point of Accuracy, and watch for a different check message. Above, the Lurker has just dropped to moderate Evasion, so it had high Evasion when I had +27 (or more) Accuracy.

Um, Khaki... you still do not know what your total Accuracy is.
Patience, Lia; I was just getting to that. It turns out that you will need one last thing to calculate your Hit Rate (%), and there are more rules:

• When your Axe skill is ≤ 200:
• Your total Accuracy = floor { [ ( Axe Skill ) + ( DEX / 2 ) + ( gear Accuracy ) + ( Accuracy from Job traits / abilities ) ] * [ 1 + ( Accuracy % from food  / 100 % ) ] }

• When your Axe skill is > 200: 
• Your total Accuracy = floor { [ 200 + floor [ ( Axe Skill - 200 ) * 0.9 ] +  ( DEX / 2 ) + ( gear Accuracy ) + ( Accuracy from Job traits / abilities ) ] * [ 1 + ( Accuracy % from food  / 100 % ) ] }

The floor function means you round whatever is inside the brackets down to the nearest integer (see notes below).
 

Note: these formulas only apply to one-handed weapons; for two-handed weapons, use floor ( 3 * DEX / 4) instead of floor ( DEX / 2 )

 

Ex. 1) Khaki has eight Axe merits, fully-leveled Axe skill, and used Sole Sushi for the test above. What is the Mamool Ja Lurker's Evasion?
We start by calculating what we know, my total Accuracy.

My total Accuracy = floor { [ 200 + floor [ ( Axe Skill - 200 ) * 0.9 ] + ( DEX / 2 ) + ( gear Accuracy ) + ( Accuracy from Job traits / abilities ) ] * [ 1 + ( Accuracy % from food  / 100 % ) ] }
My total Accuracy = floor { [ 200 + floor [ ( 285 - 200 ) * 0.9 ] + [ (66 + 21 ) / 2 ] + ( 27 ) + ( 0 ) ] * [ 1 + ( 15%  / 100 % ) ] }
My total Accuracy = floor { [ 200 + floor [ ( 85 ) * 0.9 ] + [ ( 87 ) / 2 ] +  27 ] * [ 1 + ( 0.15 ) ] } 
My total Accuracy = floor { [ 200 + floor [ 76.5 ] + [ 43.5 ] +  27 ] * [ 1.15 ] }
My total Accuracy = floor { [ 200 + 76 + 43.5 +  27 ] * [ 1.15 ] }  
My total Accuracy = floor { 346.5 * [ 1.15 ] }
My total Accuracy = floor { 398.475 } 
My total Accuracy = 398

Therefore:
My total Accuracy < Lurker's Evasion - 30
398 + 30 < Lurker's Evasion - 30 + 30
428 < Lurker's Evasion
Lurker's Evasion > 428

FFXIclopedia has listed the Evasion values under Mamool Ja Lurkers to be 424 (level 81), 429 (level 82), and 434 (level 83), respectively. Since my Lurker was VT, the last value is ruled out immediately because VT mobs can only range from levels 79 to 82. Therefore, the data suggests my Lurker was level 82.

Once you know your enemy's Evasion, you can determine your Hit Rate (%) on that foe. Ideally, you want 95% Accuracy for both your melee hits and WSs, so let us perform a sample calculation to illustrate this point.

Ex. 2) Let us say the Lurker above has exactly 429 Evasion. How much Accuracy would Khaki need to have a 95% Hit Rate on said Lurker?

Estimated Hit Rate (%) = 75 + [ ( Your Accuracy - Monster's Evasion ) ] / 2 + [ ( Your Level  - Monster's Level ) * 2 ]
95 = 75 + [ ( Your Accuracy - 429 ) ] / 2 + [ ( 75 - 82 ) * 2 ]
95 = 75 + [ ( Your Accuracy - 429 ) ] / 2 + [ -7 * 2 ]
20 = (Your Accuracy - 429 ) / 2 + [ -14 ]
34 = (Your Accuracy - 429 ) / 2
68 = Your Accuracy - 429
Your Accuracy = 497

Therefore, I would need 497 Accuracy to maintain a 95% Hit Rate on level 82 Lurkers. For most BSTs, this amount would be difficult to achieve, but do not fret, most enemies do not have Evasion values anywhere near as high.















Originally, I was also planning to calculate the optimum Attack value one should possess, but according to FFXIclopedia, the damage formulas were changed last September. As such, I have decided to skip the calculations.















This picture would have been used to calculate my Hit Rate (%) using my TP set, but the calculations are relatively similar.















As such, I have decided to omit these calculations and leave it as an exercise to the reader.

You can come out now, Snippy! 



Notes:

a) The floor function, commonly written as floor (number) on FFXIclopedia, is a mathematical function used to truncate numbers to the nearest integer.

For example:

floor (5.32313) = 5
floor (-1.9323) = -2
floor (-3.4000) = -3
floor (0.00000) = 0