Combat/Artillery Spotting

This article is under construction, therefore the content below are subject to change The article is already being adopted and currently under renovation.

Page Adopted By: Homuhomu123 Please contact this person before making any major (non-grammar, typo correction, redesigning etc.) edits on this article.

Recent Updates

• Dec 31, 2014
  • ASTRE (artillery spotting trigger rate estimate) Project mid-term report working in progress. This will serve as a preliminary, experimental proof for the credibility of the trigger chance estimates.
• Dec 19, 2014
  • Translation added for the Japanese source data (艦これ-チラ裏検証), from which fundamental assumptions were made

Introduction:

This page studies the trigger rates & effectiveness of Artillery Spotting, based on credible in-game testing. An optimal use of Artillery Spotting could considerably improve your fleet's daytime combat performances.

Please be aware on the part of Artillery Spotting trigger rate estimate. They are not 100% accurate, or even close to the actual codes written. However, the more battles you proceed, you should find those estimates being very close to the actual ones. The estimate formula are constantly being revised, not yet mature (error ~5%), thus more experiments are being conducted for refinement.

In brief, Artillery Spotting consists of two types of attack: Cut-In [CI] & Double Attack [DA]. When activated, the attacking ship receives a damage output (post-cap) & accuracy bonus. More detailed explanations could be found on the page Game Mechanics -> Artillery Spotting .

Typical Set Ups for Artillery Spotting:

Double Attack

• 2 x Main + 1 Seaplane........................................(basic setup)
• 2 x Main + 1 Seaplane + 1 Seaplane
• 2 x Main + 1 Seaplane + 1 Radar........................(highest DA chance)

>> DA Damage: 120% (post cap) x 2. More powerful for ships with high shelling accuracy and against higher evasion, lighter armor units.

Cut-In

• 1 x Main + 1 x Sec + 1 Seaplane...................................(basic setup)
• 1 x Main + 1 x Sec + 1 Seaplane + Radar......................(highest CI chance)
• 1 x Main + 1 x Sec + 1 Seaplane + AP Shell

>> CI Damage: 110% / 120% / 130%. Works well for ships with high firepower while giving more chances for Artillery Spotting.

>> Set up #2 triggers either secondary gun CI (110%) or radar CI (120%).

Hybrid (DA+CI)

• 2 x Main + 1 x Sec + 1 Seaplane
• 2 x Main + AP Shell + 1 Seaplane

>> CI Damage: 130% / 150%. More CI expected than DA. Giving the highest base rate for triggering Artillery Spotting.

The Trigger Chance of Artillery Spotting: (Beta ver.)

Possible factors are listed below, followed by their estimated effects. These values / formula might be far from the actual ones, but they do give good estimates for the activation rates. For more info on how each factor was evaluated, you may consult here.

The first 5 factors are derived from 艦これ-チラ裏検証- (click here for a translated version) and can be verified in future experiments. In addition, these hypothesis will be used as fundamental assumptions in experiment data analysis.:

1. Being the flagship / 旗艦 (+15% for both rates)
2. Radar & type / 電探 (+30% CI chance, +13% DA chance, maximum)
3. Air Supremacy or Superiority / 制空権の状態 (-12% for both if only Air Superiority is achieved)
4. Fleet total LoS / 艦隊合計索敵値/ (+8% DA rate, +10% CI rate, per 100 additional LoS)
5. LoS Values on Seaplane / 水上機の索敵補正値 (minimal effects)

The following factors have negligible effects on the trigger rates:

The following factors might have an effect on the trigger rates:

1. Fatigue / 疲労度 (No effects ?? Severe fatigue penalty was estimated to be -12% on DA chance, before Xmas update, 2014)
2. Health state / HP (Negligible effect ?? )
3. Level / レベル (Negligible effect ?? Assumption based on test results here)
4. Formation / 陣形

Detailed Explanation:

1. Before we start, let's assume a standard situation, in which Fleet total LoS = 300, test ships are beyond minor damage(小破未満) and morale condition = 49. Fleet formation Line Ahead, and Air Supremacy (AS+) is achieved for every battle. Based on test results from 艦これ-チラ裏検証 (click here for a translated version), we may come up with following hypothesis:

- BB(V) equipped with 2 x Main & 1 seaplane has DA rate ~ 50%.

- CA(V) quipped with 2 x Main & 1 seaplane has DA rate ~50% ??

- BB(V) equipped with 1 x Main + 1 x Secondary & 1 seaplane has CI rate ~ 50%

- CA(V) equipped with 1 x Main + 1 x Secondary & 1 seaplane has CI rate ~50% ??

- It was suspected that CLs & some CAs have 5% lower DA/CI base rate ??

2. As total fleet LoS incremented from 300 -> 400, the trigger rates increase slightly:

- DA rate + 8%, per 100 additional LoS, approximately.

- CI rate + 10%, per 100 additional LoS, approximately.

- Linear relation at any LoS level ??

3. If an additional seaplane scout is added onto the 4th slot:

- DA rate +5% ??

- CI rate +0% ?? 

- Actual effects are to be further determined. 

4. If we replace the extra seaplane with a radar, and compare the results to those from the standard situation:

- DA rate rises by 4 % ~ 13 % approximately, depending on the accuracy stat of the radar ??

- CI rate rises by ~30% (surface radar) or ~26% (AA radar), depending on the LoS stat of the radar ??

- List of radars with their Estimated DA/CI rate modifier (Require further verification)

	CI chance bonus Estimate	LoS stat	DA chance bonus Estimate	Accuracy stat
No.22 Surface	+27%	+5	+4%	+3
No.22 Kai-4 Surface	+27%	+5	+13%	+8
No.32 Surface	+30%	+10	+13%	+8
FuMO25 AA Radar	+26%	+9	+14% ( ?? )	+10
No.14 AA Radar	+25% ??	+5	+6% ( ?? )	+4
No.21 AA Radar	+22% ??	+4	( ?? )	+2

5. Different seaplane scouts vary slightly in the DA chance bonus.

- Type 0 Observation Plane & Prototype Seiran (+ 6 LoS) give the highest bonus. (+2%) ??

- Night Scout (+ 3 LoS) gives less bonus on DA chance (-2%) ??

- DA chance bonus depends on both stats ??

- Different seaplanes have no effect on CI chance ??

- This part is currently neglected in DA/CI rate estimation.

- List of seaplanes with their Estimated DA rate modifier (Extremely rough estimates, NOT used in calculation)

	LoS stat	DA chance bonus Estimate	Accuracy stat
Night Scout	+3	-2% ??	+1
Type 0 Recon	+5	+0% ??	+1
Ar196 Kai	+5	+0% ??	+2
Zuiun (634 Air)	+6	+1% ??	+1
Type 0 Observation	+6	+2% ??	+2

6. For standard BB(V)s, aka non-Yamato class BBs, radars could be replaced by AP Shells for a cut-in setup (Main / Secondary / AP / seaplane), which gives a 20% trigger chance bonus on CI. However, you could also use AP shells (or Secondary) for a hybrid set up (2 Main / AP (or Secondary) / seaplane). In the standard situation, the combined Artillery Spotting chance is about 70%.

- AP shell hybrid setup (with 41cm x 2): CI = ~38% & DA = ~32%. ??

- AP shell hybrid setup (with 46cm x 2): CI = ~43% & DA = ~27%. ??

- Secondary gun hybrid setup: CI = ~50% & DA = ~20%. ??

- For hybrid setup, every 100 additional LoS will only increase CI chances by 5%. ??

- Replacing Type 0 Recon by Type 0 Observation Seaplane will increase DA rate by 3%. ??

- These estimates are based on very limited test results, thus lower credibility.

- Brief Conclusion: Huge caliber guns and/or secondary gun on standard BB(V) would trade some DA for more CI chances.

7. If Air Superiority [AS] rather than Air Supremacy [AS+], then both rates fall significantly:

- Both CI & DA chance falls by at least 12%

- In the case of a hybrid setup, CI chance falls by 11% while DA rate -7%. ??

- If you're using the hybrid setup, it's more recommended to achieve Air Supremacy (AS+) for your fleet.

8. The flagship has a significantly higher chance (+15%) of triggering Artillery Spotting 

- In the case of a hybrid setup, CI chance +7.5% while DA rate +7.5%.

File:-チラ裏検証-.jpg

800x800px

Image source: 艦これ-チラ裏検証- .

Explanation: Blue = DA, Yellow = CI, Brown = Single attacks.

1. TOP LEFT: Trigger rates for flagship (outer) & companion ship (inner) with hybrid setup
2. TOP RIGHT: The plotting of artillery spotting rate versus fleet total LoS (flagship status &/or equipment bonus NOT excluded)
3. BOTTOM LEFT: Flagship & her companion ships with DA basic setup.
4. BOTTOM RIGHT: Flagship & her companion ships with CI basic setup.

Artillery Spotting Trigger Rate Estimate: (Beta ver.)

NOTE: As mentioned before, these calculation only serves as rough estimates on your ship's artillery spotting chances. More credible tests (Sample size > 170) are required to come up with a better formula. Deviations from actual test results are supposed to be less than 5%, otherwise reworking on the formula itself should be considered. This does not include effects from fatigue, HP status(中破), and undetermined factors like formation, level differences (>>10), a few special ships (esp. CA) or maps, etc. The estimates for which their true probability is closer to 50% will be less accurate, and vise versa.

Here's an example calculation in chart format, with sign convention:

Base Rate	Flagship Status	Air Supremacy Penalty	Radar Modifier	Fleet LoS Modifier	Seaplane Modifier
50%	+15%	-12%	[+13%]	(+10%)	<+0%>

Sample Calculation for DA:

1) Fuso Kai, AS+, FLoS = 300, equipped with 2 main, #32 radar & Type 0 Obsv. will have a:

• DA chance of ...
• 50%(BB Base) + 13%[Radar Modifier] + 0%(LoS Modifier) +1%<Seaplane> = 63%

2) Prinz Eugen Kai, AS+, FLoS = 300, equipped with 2 main, FuMO32 & Ar196 will have a:

• DA chance of ...
• 50%(CA Base)+ 16%[Radar Modifier]+ 0%(LoS Modifier) +0%<Seaplane> = 66%

3) Chikuma Kai, AS+, FLoS = 400, equipped with 2 main, #22 radar & Type 0 Recon will have a:

• DA chance of ...
• 50%(CA Base)+ 4%[Radar Modifier]+ 8%(LoS Modifier) + 0%<Seaplane>= 62%

4) Haruna Kai, {flagship}, AS+, FLoS = 300, equipped with 2 main, #22 radar & Type 0 Recon will have a:

• DA chance of ...
• 50%(BB Base)+ 15%{Flagship Modifier} + 4%[Radar Modifier]+ 0%(LoS Modifier)= 69%

5) Mutsu Kai, {flagship}, AS, FLoS = 300, equipped with 2 main guns, #22 radar & Type 0 Recon will have a:

• DA chance of ...
• 50%(BB Base)+ 15%{Flagship Modifier} - 12%(Air Superiority) + 4%[Radar Modifier]+ 0%(LoS Modifier)= 57%

Sample Calculation for CI:

1) Fuso Kai, AS+, FLoS = 300, equipped with 1 main + 1 sec, #22 Surface radar & seaplane will have a:

• CI chance of ...
• 50%(BB Base)+ 30%[Radar Modifier]+ 0%(LoS Modifier) = 80%

2) Atago Kai, AS+, FLoS = 300, equipped with 1 main + 1 sec, #14 AA radar & seaplane will have a:

• CI chance of ...
• 50%(CA Base)+ 25%[AA Radar Modifier]+ 0%(LoS Modifier) = 75%

3) Mutsu Kai, AS+, FLoS = 400, equipped with 1 main + sec, AP shell & seaplane will have a:

• CI chance of ...
• 50%(BB Base)+ 20%[AP Shell Modifier]+ 10%(LoS Modifier) = 80%

4) Kumano Kai, AS+, FLoS = 400, equipped with 1 main + 1sec, #32 Surface radar & seaplane will have a:

• CI chance of ...
• 50%(CA Base)+ 30%[Radar Modifier]+ 10%(LoS Modifier)= 90%

Sample Calculation for Hybrid Setup: (Lower Credibility)

1) Mutsu Kai, AS+, FLoS = 400, Type 0 Recon, AP shell setup with 41cm x 2:

• Total artillery spotting rate = 70%(BASE) + 5%(LoS Modifier) = 75%.
  • CI% = 38%(AP BASE) + 5%(LoS Modifier) = 43%
  • DA% = 32%(AP BASE) = 32%

2) Kongou Kai Ni, AS+, FLoS = 400, Type 0 Obsv., AP shell setup with 46cm x 2:

• Total artillery spotting rate = 70%(BASE)+ 5%(LoS Modifier) + 3%<Type 0 Obsv.> = 78%
  • CI% = 43%(AP BASE, Overload) + 5%(LoS) = 48%
  • DA% = 27%(AP BASE, Overload) + 3%(Obsv.Seaplane) = 30%

3) Nagato Kai, AS, FLoS = 400, Type 0 Obsv., AP shell setup with 46cm x 2:

• Total artillery spotting rate = 70%(BASE) - 18%(Air Superiority)+ 5%(LoS Modifier) + 3%<Type 0 Obsv.> = 60%
  • CI% = 43%(AP BASE, Overload) - 11%(Air Superiority)+ 5%(LoS) = 37%
  • DA% = 27%(AP BASE, Overload) - 7%(Air Superiority)+ 3%(Obsv.Seaplane) = 23%

Effectiveness of Artillery Spotting

Some of the suggestions are derived from article All About Firepower by Nainodel.

DA:

- Lower activation rate compared to daytime CI.

- It gives accuracy boost.

- More dependent on shelling accuracy if you wish to maximize your damage output (120% post cap x 2)

- With appropriate caliber gun set up (eg. 35.6cm x2 for Fuso), ceteris paribus, BB would possess higher DA accuracy than CA.

- If Head-On, T-disadvantage and/or low firepower, DA would usually do a double-scratch on enemy with heavy armor.

- Not feasible with AP shell, unless using hybrid setup.

- Recommended for enemy with lower armor than or equivalent to Ru-Class Battleships.

- If either attack could wreck the enemy (eg. low armor w/ high evasion), preferably use DA due to higher chance of hitting the target.

CI:

- Activate frequently during daytime battle (w/ radar).

- It gives accuracy boost. (equivalent to DA ??)

- Works well with AP shells. Recommended when dealing with Ru-Class Battleships and above.

- Highest damage (single strike): 130% post cap for AP shell CI setup; Or 150% post cap, for AP shell hybrid setup.

- Accuracy plays an important role in CI, since you have only 1 chance to hit the enemy (2 for DA).

- For an AP hybrid setup, overload (eg. 46cm x2 on Nagato Class) might shift some DA chances into CI. Therefore, for BBs with low firepower, you may consider using an overload setup for more firepower & CI when encountering high armor, low evasion enemies. (Hypothesis Only)

- Since AP shells are not accessible to CA(V), their maximum CI damage is 120% post cap with radar. However, if secondary-gun hybrid is used for CA, it could be 130%, but reliability has not been tested. (Lower activation chance?? Lower shelling accuracy expected).

- Read more: Comparative study on DA/CI with sample enemies .

Uncertainty

• It seems that there should be a CI trigger-rate-cap above 90%. It doesn't make sense to have a CI chance more than 100%, for a set up like BB (50%) + radar [30%] + flagship{15%} + LoS modifier (10%) = 105%.
• Test results from CA are more volatile. It seems that for some CAs, LoS doesn't really affect their CI/DA chances ??