User blog:Fujihita/Complete deck building guide for Spring 2016 E-2

Forewords
I don't normally write map guides but I'll make an exception for Spring 2016 Event, E-2 map, for a very good reason. That reason is the strict equipment requirement of E-2, effectively preventing a great number of casuals and new players from clearing this map. Heck! Even some of the more seasoned players with multiple WG-42 and Daihatsu struggle in this map.

Considering Spring 2016 has FOUR ship locks, it shouldn't come as a surprise when players need to be stringent when it comes to fleet composition. Thus, I'll provide in this guide step-by-step deck building instruction so that anyone can build their own fleet and clear this map based on their own circumstances.

There's a motivation behind this voluntary act of mine. I, as wiki editor, cannot stand and watch a great portion of the population gets locked out of the latter parts of the events. We need more cannon fodd--I mean, brave souls who can venture into uncharted waters and contribute information, and by no mean this is the privilege or responsibility of the veterans. Hence the reason why this blog is written now.

The Threats
First, I'll perform the risk analysis of this map. This is the first step one should take before attempting to build any composition. Spring 2016, E2 has the following threats:


 * 1) Wo-class hellcat
 * Node B is bad news for any single-fleet and double [Tsu-class elite] in line ahead formation (high torpedo accuracy) make the node even more perilous.


 * 2) Double Ru-class and Nu-class
 * Node F is even worse news for single-fleet, especially when these [Ru-class flagships] are in Line ahead/Double line. Considering node F is the third battle node, which means low fuel and less evasion for our girls, this node is even more of a threat than node B.


 * 3) Multiple closing torpedo threats
 * E-2 is infested with high torpedo power Abyssal. [Ri-class flagship], [Tsu-class elite], [He-class flagship], [Ho-class flagship], [Any DD late model] and all forms of [PT Imp packs] are major threats for light ships.
 * A special note on [Tsu-class elite], [Ri-class flagship], [He-class flagship], [Ho-class flagship] is that, they are likely to resist shelling from mid-tier DDs and CLs. Due to their evasion and armor, the first three ships can resist non-artillery spotting CA attacks as well.


 * 4) Submarine opening torpedo
 * [Ka-class flagship] and [Ka-class elite] cannot be disabled, at least not reliably, without any ASW equipment.
 * There's no saving for the opening torp. Pray hard is the only solution.


 * 5) Powerful installations at boss
 * Boss fleet consists of bulky [Artillery Imps] whose firepower can reduce a BB to scrap metal easily.
 * The boss of this map is [Depot-hime] who is lovingly dubbed by the community as DJ-hime. Her final form, especially in Hard mode has incredibly high armor, meaning even CA with Type 3 shell can have trouble inflicting enough damage to her in yasen.


 * 6) PT Imp packs
 * These benevolent devilish creatures are the bane of heavy ships. Luckily, they share the same vulnerability to WG-42 and Type 3 shell as the installations so they can be destroyed reliably in this map.

Fleet Compositions
Of the 6 threats above:
 * 1) and 2) can be completely or partially avoided via branching rules.
 * 3) can be mitigated by via the usage of support expedition.
 * 4) cannot be avoided or mitigated at all, nor should you attempt to do so.
 * 6) is naturally eliminated as stated above.

I'll look into the branching rules first. There are three branches to use in this map:


 * A -C- E -H- I - G -Boss
 * Achievable via 3DD + 1CL + 1CA/CAV + (1CA/CAV or fast CVL/AV).

Ideally, these should be the composition variants to use but they all require uncommon anti-installation equipment such as WG-42 and any variant of Landing Craft (Daihatsu). Threat 3) and 5) are particularly prominent for these compositions due to the lack of second shelling phase. With enough planes, these compositions can achieve AP/AS preboss. Notably, the compositions with CVL can even guarantee AS at boss in final form.


 * B - E -H- I - G -Boss
 * Achievable via 3DD + 1CL + 1CA/CAV + FBB.

Without enough of the required anti-installation equipment, one should consider accepting threat 1), the Wo node, for extra firepower against the boss. By using a DD on AACI setup (preferably Akizuki-class), Wo's airstrike power can be significantly reduced, however, it's problematic considering Wo-class can also get 2 devastating shelling strikes due to the presence of FBB.

It is nearly impossible to AP this node, even with Italia/Roma and CAV using Zuiuns. However, it is possible to AP or even AS node I (Ri flag node) with the aforementioned ships.


 * B - E - F - G -Boss
 * Achievable via 2DD + 1CL + 1CA/CAV + FBB/BB/BBV + CVL.

Finally, this is the "brute force" composition for those who do not have any anti-installation equipment other than Type 3 shell, which is craftable and there is no excuse for not having any. This fleet provides extraordinary firepower against boss fleet and also guarantee AS with three double chevron fighters. However, going through both Wo node and Ru node poses a serious problem pre-boss. Not to mention, the cost of running this kind of fleet is no laughing matter.

If even the brute force fleet doesn't cut it, consider dropping the difficulty.

Ship Roles & Equipment Load-outs
Here are some example load-outs that fulfill a specific role:

Air team: CA + fast CVL
Only bring Night scout when AS is guarantee at boss. This mean night scout should be used with a fast CVL in fleet. The required AS value at boss is ~132, you will need ~142 for compositions that don't go through Wo node, or ~150 for compositions that do go through Wo. Depending on the CVL you're using and the quality of your fighter planes, there might not be enough space for SCAMP.

It is possible to supplement the fighter power using CAV and seaplane bombers. Personally, I prefer this combo since I value the night scout highly and pure CA is generally stronger than CAV in yasen. The AS requirement is so strict that Saiun is sacrificed for the sake of getting AS at boss.

Air team: CAV + CAV
This combo achieves AP at node I in last dance, just barely. If any of the Zuiuns lose its rank, this combo might even fail to get AP. Other than that, the opening airstrike from these seaplanes can wreck havoc to one or two enemy destroyers/PT imps.

Boss killer: 4-slot CL
The strongest yasen combo against installations among CLs. This setup can deal up to 100 critical damage during daytime single attack as well.

Boss killer: Single-attack landing craft DD
The WG42 is additive firepower against installations while Daihatsu is multiplicative. It is necessary to wield at least one WG42 to increase the non-existent base firepower of the DD before multiplying. In Layman's terms, 0 x 3.5 x 3.5 = 0 but (0 + 50) x 3.5 = 175

This is also why the double attack variant using 2x main guns and Daihatsu doesn't work too well on DDs.

Boss killer: Single-attack WG-42 DD
Stacking WG-42 has diminishing return so stacking more than 2 WG-42 on one ship is both risky and inefficient. I recommend setting up a double-attack DD with the extra WG-42 as seen below:

Boss killer: Double attack DD
Double attack DDs are arguably disadvantageous. Single-attack DDs can deliver substantial damage during day battle and even in moderate damage condition. Meanwhile, the DA setup delivers the most damage during night battle and hence can be canceled completely by heavy damage. Furthermore, in ideal conditions, the overall damage potential of either setup is the same.


 * Single attack
 * ~100 daytime, ~100 night time.


 * Double attack
 * ~50 daytime, ~150 night time (actually, more like ~100 because one of the hits is likely to scratch or miss).

Boss killer: Double attack CA
Obvious load-out is obvious. Remember, CA is better than CAV in term of firepower so always use CA if possible.

Fleet Arrangement
This is a systematic way to build a deck. First, select the fleet composition based on branching rules, weighing the risks and benefits. Then, assign roles and load-out to ship girls. Finally, arrange the ships in a specific order to match the strategy of yasen firing order.

In this case, the second clause of the rule "Strong ships fire first" is used since devastating the entire enemy fleet isn't really an option (it is but not anywhere remotely reliable). Therefore, I'm stacking the primary boss killers at the bottom while leaving enough firepower in slot 2 and 3 to turn cancel the artillery imps if I need to.


 * Fleet arrangement:
 * 1) Primary boss killer (Night scout carrier will benefit from flagship's artillery spotting bonus)
 * 2) Secondary boss killer (Scratch boss and turn cancel/sink an artillery imp)
 * 3) Secondary boss killer (Scratch boss and turn cancel/sink an artillery imp)
 * 4) Primary boss killer / wild card
 * 5) Primary boss killer / wild card
 * 6) Primary boss killer (if you have THAT many boss killers) / wild card.


 * Ranking of boss killer setup by night battle strength vs. boss:
 * Primary boss killers: 4-slot CL > CA > single-attack DD
 * Secondary boss killers: CAV (debatable) > double attack DD.


 * Recommendations:
 * Ideally, I recommend 2 secondary boss killers and 2 primary boss killers. It is possible to run one fewer secondary boss killer. However, if equipment or ship constraints lower the number further, do consider changing the composition to a variant that better fit one's arsenal.
 * Keep in mind when choosing the ships to fulfill a specific role is that some better ships (such as Ooyodo and Yuubari as boss killers) can be saved for later operations; in particular, the notorious E-5 and E-6 locks. Saving better ships for latter maps might also be a reason why one can attempt a perceived weaker composition intentionally--an act that should only be done at one's own discretion.

Final Deck
Good luck and happy salting, Admirals!