Naval AA worth it in LaR?

[marcelo r. r.]

My late game i normally invade USA by 50's i like to pursue their reimaning navy, but normally they had 4k+ naval bombers and punch hard on navy.

i never experimented it before, im in 1944, already had a decent navy, im willing to make a full AA light cruisers to try it. then i had some questions.

a) the Naval AA "protect" entire fleet or its individual(i mean no matter if u put 10 full AA light cruisers, your poor single DD1 is doomed anyway?
b) anyone had did some tests/experiments in this to share?

 

[sterrius]

My late game i normally invade USA by 50's i like to pursue their reimaning navy, but normally they had 4k+ naval bombers and punch hard on navy.

i never experimented it before, im in 1944, already had a decent navy, im willing to make a full AA light cruisers to try it. then i had some questions.

a) the Naval AA "protect" entire fleet or its individual(i mean no matter if u put 10 full AA light cruisers, your poor single DD1 is doomed anyway?
b) anyone had did some tests/experiments in this to share?

For naval. You want each ship AA to be as high as you can without going too crazy. This is because individual ship AA is a important value of the formula.
but the main value is really the Fleet AA. As those can easily go into the hundreds. Specially if you DD have something like a Dual Purpose gun.
Fleet AA at high numbers can really help to reduce Air Dmg.


How AA work in naval by kroganelite

#1 Scenario: A fleet of 10 ships with AA value of 1 each ( (1 + 10 * 0.2 )0.2 ) * 0.15 = 0.187 or 18.7% damage reduction due to AA to each ship(since they all have the same AA value)

#2 Scenario: A fleet of 20 ships with AA value of 5 each ( (5 + 100 * 0.2 )0.2 ) * 0.15 = 0.286 or 28.6% damage reduction due to AA to each ship(since they all have the same AA value)

To simplify, we can chart how much fleet AA you would need to get certain air damage reduction for each ship guaranteed:

As you can see it's diminishing returns.

HOI4: Fleet AA damage reduction

Sheet1 Fleet AA,Damage reduction 1,0.1087169496 2,0.1248829811 3,0.1354320677 4,0.143452875 5,0.15 6,0.1555705934 7,0.1604415564 8,0.1647840815 9,0.168711917 10,0.1723047532 11,0.1756207369 12,0.1787036847 13,0.1815874913 14,0.1842989519 15,0.1868596409 16,0.1892872033 17,0.1915962667 18,0.19379...

docs.google.com

Example:

Initial AA->New AA = Initial reduction->New reduction (Increment gain)

0->1 = 0%->~11% (+~11%)
1->5 = ~11%->15%** (+~4%)**
5->15 = 15%->~18.7 (+3.7%)
15->50 = ~18.7->~23.8% (+5.1%)
50->200 = ~23.8%->~31.4% (+7.6%)

 

[Paul.Ketcham]

1940 AA in particular is a pretty big jump up for AA strength, and RADAR buffs that massively from 1940 onwards. It tends to be a good idea to go for both since they have some dual-purpose utility (1940 and later AA is great for nations without air superiority). Its pretty doable to get up to 20 AA per cruiser* or battleship based on mixing DP secondaries with 1940+ radar and 1940+ AA.
*Cruisers need more equipment/tech to hit 20+, but 2 AA modules and FC can bump them up; with 3 DP secondaries and 1940 AA/radar, its closer to 12 AA)

For destroyers, however, its usually too expensive to practically get any meaningful AA rating on them without a significant cost increase for them. I'd rather build destroyers with little or no AA, and focus on max-AA cruisers and battleships (capital ships benefit individually as they tend to be the ones getting bombed, while cruisers can benefit from the stacking AA % bonuses while relying on relatively-affordable DP secondaries). The problem with arming destroyers with DP primaries is both the higher cost, but also the +1 steel for mounting them. By comparison, AA and DP secondaries don't cost steel, and can be refitted on older ships more affordably.

For some perspective, a minimalistic destroyer costs around 1100 IC with Gun-2, Torpedo-2, Depth Charge-2, and engine-2. The cost climbs to 1500+ if you try to mount DP guns, AA-3, and an extra module (whatever you want in the 3rd mounting, whether more torpedoes, depth charges, AA, guns). Its reasonable as the US given your massive steel stockpiles and the fact that you are going to be operating against a lot of enemy aircraft (the Axis really can't go head-to-head vs the Allies without naval superiority), but that's about it. Britain, Germany, and Japan really lack the steel and NIC to produce high-cost destroyers for good AA ratings without compromising on other things like cruisers (or steel-expensive ground equipment like tanks or 1942 rifles). A high-AA destroyer is also still only going to be likely 10+ on AA for that cost.

 

[marcelo r. r.]

thanks, @sterrius @Paul.Ketcham for advice,

basically is 1944~1945, its time to naval invade far away zones, economy inst a trouble, i fine tuned the economy and i have 100 naval yards, and a already "big size fleet", but the usa+uk late game put tons of naval bombers like 4k+.

so basically according to sterrius advice its worth it, i will make some big specialized AA light cruisers and destroyers.,

 

[sterrius]

1940 AA in particular is a pretty big jump up for AA strength, and RADAR buffs that massively from 1940 onwards. It tends to be a good idea to go for both since they have some dual-purpose utility (1940 and later AA is great for nations without air superiority). Its pretty doable to get up to 20 AA per cruiser* or battleship based on mixing DP secondaries with 1940+ radar and 1940+ AA.
*Cruisers need more equipment/tech to hit 20+, but 2 AA modules and FC can bump them up; with 3 DP secondaries and 1940 AA/radar, its closer to 12 AA)

For destroyers, however, its usually too expensive to practically get any meaningful AA rating on them without a significant cost increase for them. I'd rather build destroyers with little or no AA, and focus on max-AA cruisers and battleships (capital ships benefit individually as they tend to be the ones getting bombed, while cruisers can benefit from the stacking AA % bonuses while relying on relatively-affordable DP secondaries). The problem with arming destroyers with DP primaries is both the higher cost, but also the +1 steel for mounting them. By comparison, AA and DP secondaries don't cost steel, and can be refitted on older ships more affordably.

For some perspective, a minimalistic destroyer costs around 1100 IC with Gun-2, Torpedo-2, Depth Charge-2, and engine-2. The cost climbs to 1500+ if you try to mount DP guns, AA-3, and an extra module (whatever you want in the 3rd mounting, whether more torpedoes, depth charges, AA, guns). Its reasonable as the US given your massive steel stockpiles and the fact that you are going to be operating against a lot of enemy aircraft (the Axis really can't go head-to-head vs the Allies without naval superiority), but that's about it. Britain, Germany, and Japan really lack the steel and NIC to produce high-cost destroyers for good AA ratings without compromising on other things like cruisers (or steel-expensive ground equipment like tanks or 1942 rifles). A high-AA destroyer is also still only going to be likely 10+ on AA for that cost.

Problem of DD`s n a strike fleet is they need AA. They are by far the most numerous and the ones that will really bring the AA fleet number to skyrocket or stay low.
Also their dmg outside of torpedos is useless so outside of dying and shooting torpedo AA is the only job they can have.

Also if you're making a DD for strikefleets you don´t need Depth Charge 2 or gun II. Quantity will make sure any submarine found will quickly die to the absurd amount of depth charges throw at him.

For 1344 IC you can have a 1936 DD with 6.1 AA. Even a almost barebone DD II/III is gonna cost around 1200. So the sacrifice for a good AA value is minimal.
You can try to have some true barebone DD`s, those do cost around 900 but i find this pretty expensive for just extra 40-50HP on a fleet.

Fire control modules are great because they're cheap and DD`s have a good amount of reliability.

this is what i would use for example as Japan for a strikefleet! Only difference Japan can have DD III or at least DD´s II with Engine III

 

[Paul.Ketcham]

Problem of DD`s n a strike fleet is they need AA. They are by far the most numerous and the ones that will really bring the AA fleet number to skyrocket or stay low.
Also their dmg outside of torpedos is useless so outside of dying and shooting torpedo AA is the only job they can have.

Also if you're making a DD for strikefleets you don´t need Depth Charge 2 or gun II. Quantity will make sure any submarine found will quickly die to the absurd amount of depth charges throw at him.

For 1344 IC you can have a 1936 DD with 6.1 AA. Even a almost barebone DD II/III is gonna cost around 1200. So the sacrifice for a good AA value is minimal.
You can try to have some true barebone DD`s, those do cost around 900 but i find this pretty expensive for just extra 40-50HP on a fleet.

Fire control modules are great because they're cheap and DD`s have a good amount of reliability.

this is what i would use for example as Japan for a strikefleet! Only difference Japan can have DD III or at least DD´s II with Engine III

Its a fair point for certain theatres, and my main issue was with the DP primary (very high cost in both steel and IC). That said, there are a few key issues I always would recommend keeping in mind when building destroyers:

1.) When are you building them? You typically start with a lot of low-tech ships that need refits at the start of the game, and considering that the key techs you need are all 1940 or later, you're going to be manufacturing a lot of ships prior to that which won't likely have high AA (even when I rush DP guns, screens are going to be closer to 10 AA for cruisers and 3 for destroyers for 1936-tech). That means that you have your starting fleet plus 3-4 years-worth of new vessels that all need AA refits, and most navies start with a serious deficit in screens.

2.) Where are they going to operate? Any destroyers operating in deep oceans won't benefit from AA, while other environments have limited airbases in range (whether due to neutral countries or low value/indefensible states where new airfields aren't worthwhile). For that reason, I tend to split DD production between air-safe regions and hostile coastlines (meaning one class with no AA and one with 1-2 AA), and emphasize cruisers over destroyers for operating in coastal waters (which can mount more AA in the first place). To some degree this is only partially-doable, but its still a question of whether you want more ships or slightly-better bombing damage mitigation.

3.) Is the larger threat from air attack or naval attack? Low-tech naval bombers get shredded by high-tech flak, meaning that in the late game the AI often can't effectively drive back ships anymore without itself suffering massive attrition. On the flip side, if you're trading torpedo launchers or guns for flak (I particularly like the DD-2 gun compared to the anemic DD-1 gun, only 30 IC difference), you're talking far-more substantial costs in torpedo or gun attack than simply adding the occasional extra DD.

I'm still in favor of mounting AA for some destroyers, but realistically at the start of the game you need quantity over quality just to screen starting capital ships for most navies, and later on you usually want to make cruisers rather than destroyers to clear out enemy screens (and properly-built CLs will slaughter the starting CLs for most navies). Germany in particular is a nation that hardly needs destroyers at all due to its lack of trade convoys (presumably), meaning it can go all-out for high-quality cruiser fleets.

Edit: Spelling

 

[sterrius]

@Paul.Ketcham
those are all fair points and unless we start to focus on specific countrys to reduce the scenarios i don´t think we can go much further in the conversation.

if you like you can choose a country and im up to keep talking in better ways of giving the enemy player/AI a new life in the bottom of the ocean.

Anyway i hope our conversation help some players to understand AA and the naval system better.