User:Jigaraphale/Sandbox/7

The "hidden fit bonus" mechanic refers to some ships receiving bonuses or penalties when equipping certain equipment, depending on if the equipment "fits" the class or not.

• This almost exclusively refers to main guns, where each class of ship is engineered to carry up to certain gun calibers, and so, equipping gun turrets of the right caliber or lower will imply an accuracy bonus, whereas using larger calibers will result in some overweight penalties.
• Not to be confused with visible Equipment Bonuses.

As hidden bonuses are unaffected by morale or fleet types (e.g. combined fleets), it can be interesting to utilize those fit bonuses as much as possible.

Such fit mechanics do not apply to abyssals.

Battleships Bonuses

Battleships receive accuracy bonuses if the guns are fit and accuracy penalties if it is overweight. How much bonus/penalty a ship receives, depends on the battleship class, the caliber and type of the gun, and whether the battle takes place during day or night.

Ship Class	IJN 35.6 cm KMS 38 cm Sov 30.5 cm RN 38.1 cm	Fr 38 cm	RM 381 mm	IJN 41 cm			USN 16 in Twin			USN 16 in Triple			RN 16 in			IJN 46 cm			51 cm Twin	51 cm Triple
				basic	Triple K2	Twin K2	Mk.I	Mk.V	Mk.VIII	Mk.7	Mk.7 +GFCS	Mk.6 mod.2	Mk.I	+AFCT	Kai +FCR	Proto	46cm	Kai
Gangut-class	+7 Sov 30.5 cm: +10	0	+1	-7			??	-5	??	-3			-9~10?	??	??	-7	-18	??	N/A
Kongou-class	+7	0	-2	-5	-5?					-5	-6~7?		-5	-6	-3	-7	-10	-10?
Bismarck-class Vittorio Veneto-class	+4	0?	+1	-5						-5	-4?		-5	??	??	-7	-10	??
Iowa-class	+4?	0?	-2?	-5						0	+2					-7	-10	??
Colorado-class	+1			+2						-2						??	??	-7
South Dakota-class												-5 M: +4.6				??	??	??
Richelieu-class	+4	+4~5	-2	-2						-5			-7	-14?	-8	-7	-10	??
Queen Elizabeth-class	+6 RN 38.1 cm: +8		+1~2	+2							-2?		+5	??	+3~4	-8	-11	??
Nelson-class	0		0	+3?							0		0			??	??	??
Fusou-class Kai/Ni Ise-class Kai	+4	0	+2	+2						0			0?			-3	-7 F+: -11?	-4?
Ise-class Kai Ni	+4?	0	+1?	+4?	+4?	+6									+2	??	-7 F+: -11?	??
Fusou-class base Ise-class base	+2	0	+2	+2						+2	+2?		+3			-3	-7	??
Nagato-class base/Kai																			0	??
Nagato-class Kai Ni	+2?	0	+1?	+5	+5	+5~6	Mutsu: +3	??	??	0				+4		-2?	-4?	-6?	Nagato: -5 Mutsu: -8	??
Yamato-class	0															+3	+3	+7	0	??
Yamato Kai Ni (FBB)	0															??	-7	??	??	-10

Note: Fit gun mechanics are still being investigated to this day, hence the values are not final and may be subject to changes. Values with a question mark either mean that it is not conclusive yet or the conclusion drawn here is not the same as the one drawn by Yumeji.

• The table shows an estimated accuracy fit bonus based on having one fit gun equipped.
• For married ships, the overweight penalty is reduced by 40% (A married Kongou with a 46cm receives a penalty of -6 instead of -10, for example).
• If more than one gun of the same class is used, multiply the modifier by the square root of number of guns. (A Kongou-class with two A class guns equipped for example, that's √2 x 7 = 9.89)
• If guns from different classes are used together, add the modifiers together. (A Kongou with a 35.6cm and 41cm mixed for example, that's 7 - 5 = 2.
• Exceptions arise where different guns of the same class give different bonuses on certain ships, notably Gangut. What would happen if you combine 30.5cm and 35.6cm is still under investigation.
• The information in this table is sourced from this spreadsheet maintained by Dewy with the relevant sources linked in the spreadsheet.
  • alternative spreadsheet

More generally, the accuracy offset can be defined with the formula:

[math]\displaystyle{ W = \sum^{\text{All Classes}} \left ( C_{k} M_{k} \sqrt{N_{k}} \right ) \% }[/math]

Where:

• [math]\displaystyle{ W }[/math] is the resulting fit bonus or overweight penalty
• [math]\displaystyle{ C_{k} }[/math] is the main coefficient of the equipped gun class. Refer to the above table for the coefficients applied to each Battleship for their respective guns.
• [math]\displaystyle{ M_{k} }[/math] is the marriage coefficient for the particular gun class. Assumes a value of 0.6 if the ship is married, and if the main coefficient is negative.
• [math]\displaystyle{ N_{k} }[/math] is the number of equipped guns for that gun class.

Cruiser Bonuses

Light Cruisers (CL/CLT)

Ship	Guns group		Accuracy bonus/penalty
	1st Gun	2nd Gun	Unmarried	Married
Default to very CL(T)	-	-	0	0
	A/B	A/B	0	2
	C	C	-5?	-1?
	D	D	-6	-3.6
	E	E
	F	F
	F	-	-3	-1.8
	G	G	-22	-17.6
Agano-class	B	-	5	7
	B	B	6	8
	F	F	-8	-6
Ooyodo	C	C	-2	-1.2
	F	F	-10	-8
Atlanta-class	E	E	0	3
Abyssals	Any	Any	0	-
	Medium Guns		-3 x N	-

• There is not enough data to pin down the exact fit accuracy formula.
• Other gun combinations fits cannot be extrapolated yet.
• There are known tests where the fit bonuses do not scale linearly with the number of guns.

Heavy Cruisers (CA/CAV)

Ship Class	14cm Twin /Kai	15.2 cm /Kai	C	IJN 20.3 cm		203mm/53	G
				Day	Night
CA(V)				0	+5 +5N?		0
Mogami-class			+2
Mogami-class Kai Ni			+5
Zara-class						+1 +1
Seaplane Tenders (AV)	-6N	-6N		-8 -10N			-8 -10N?

Note: Fit gun mechanics are still being investigated to this day, hence the values are not final and may be subject to changes. Values with a question mark mean that it is potentially outdated and might no longer be correct.

• The table shows an estimated accuracy and/or firepower fit bonus based on having one fit gun equipped.
  • The variable N refers to the number of guns of that category equipped. (Ex: 2 guns of 2N = 4 ACC)
• Bonuses from guns of different classes are simply added together.
• The night fit bonus from the 20.3cm series used to be capped at +15%. However, it is unknown whether this cap has been removed or not from the recent updates.
• There is a possibility that certain fit categories only work during the day. The possibility is plausible, but there's no concrete data proving. The alternative theory is that the night bonus from the 20.3cm series overrides any other categories.
• The information in this table is sourced from these two spreadsheets (1) (2) the latter maintained by Dewy, both with the relevant sources linked in the spreadsheet.
• As of 13th December 2018 the hidden firepower bonus of 14cm Twin Gun Mount Kai does not work/does not exist^{[citation needed]}.

Small Caliber Main Guns

As of 2017/06/23, Yura and Mutsuki/Kamikaze-classes of destroyers gain bonuses with some main HA guns .

Ship	12.7 cm Single HA Mount (LM)	12.7 cm Twin HA Mount (LM)
Light Cruisers (CL)	+4N	+2 +2N
Yura Kai Ni	+4 +10N
Mutsuki-class	+5
Kamikaze-class	??

Unknown factors:

• Only Yura K2 and Satsuki K2 were tested. It's unknown whether the other ships in the same class would receive the same bonus or whether it only works for specific remodels.
• The variable N refers to the number of guns of that category equipped (ex: 2 guns of 2N = 4 ACC).
• It is unknown whether the 12.7 cm Single HA Mount gives a fit bonus or not.
• The information in this table is sourced from this spreadsheet maintained by Dewy, but has no sources linked in the spreadsheet.

Destroyer Bonuses

Certain destroyers have a higher-than-expected hit rate when equipped with certain guns or sonars.

• The bonus accuracy likely takes the form: [math]\displaystyle{ \text{ACCURACY}_\text{bonus} = \text{C} \times \sqrt{\text{N}} }[/math]
  • N being the amount of equipment.

Known "C" values
Ship/Class	Gear	C
Tashkent/Verniy	130mm B-13 Twin Gun Mount	5
Fletcher-class	5" Single Gun Mount Mk.30 variants	4
John C. Butler-class		4
J-class	QF 4.7inch Gun Mk.XII Kai	3
	ASDICs	3
Mutsuki-class	12cm Single Gun Mount Kai 2	5

Source: [1][2]

See Also

Main data sources :

• [3]
• [4]
• [5]
• [6]
• [7]