Ship armor test

[walt526]

Is it accurate that screening ships' AA does nothing? My understanding is that a ship's AA is a function of its own AA rating and the fleet average AA (I think it was weighted at 20%). That is, there's a penalty to capital ships' AA capability if the DD and CL aren't equipped with AA, even if the screens themselves aren't targeted.

 

[Razgriz13]

If you want to take a look on data, here it is: (it might be a bit outdated)

User:Bitmode/Ship - Hearts of Iron 4 Wiki

hoi4.paradoxwikis.com

User:Bitmode/Naval warfare - Hearts of Iron 4 Wiki

hoi4.paradoxwikis.com

Naval battle - Hearts of Iron 4 Wiki

hoi4.paradoxwikis.com

Bitmode opened the source code to take those values, it might help.

Important thing for armor: non pierced armor has base 10% (20%) chance of crit, and it won't change without skills. Pierced armor will only increase crit chance, and crit is one of the most dangerous things damage wise.

Also, armor is really important to cruisers and battlecruisers, because:
-Cruiser armor can reduce damage of light guns
-Heavy Cruiser Guns can pierce battlecruiser armor

Both Battlecruiser and Battleship benefits little of speed, but cruisers can have about 5% hit chance benefit

 

[Caeric]

The more I read these analyses the more frustrated I get with the state of naval warfare. The current system is miles away from representing reality in any way. Heavy cruisers are NOT capital ships and these is no sane captain that would prioritise shooting something they cannot realistically hurt over another fellow cruisers. Neither light nor heavy cruisers were in any shape or form immune to each others guns except at very long ranges, light cruisers in the end ended up being considered better than heavy cruisers in the first place since their far higher volume of fire ended up being offsetting what a heaver gun could do on a similar amount of tonnage. Same also applies to heavy ships, whilst one might be virtually immune at longer ranges, at a short range duel no amount of armor will be enoughMixed gun batteries are long dead since the era of pre-dreadnoughts due to how innefficient it makes gunnery for example. MtG is just so goddamn half-assed its embarassing.

 

[sterrius]

. Neither light nor heavy cruisers were in any shape or form immune to each others guns except at very long ranges, light cruisers in the end ended up being considered better than heavy cruisers in the first place since their far higher volume of fire ended up being offsetting what a heaver gun could do on a similar amount of tonnage.

A light cruiser can hit a heavy cruiser if there is no Screens.
A Destroyer can do that too.

and if you put a 1 BAttleship vs 10 Destroyers they will shoot at each other even if they both lack good attacks.
And a heavy cruiser can hit a light cruiser with its heavy gun if there is nothing else to shoot.

Otherwise if you put a CA with 0 light attack vs a CL with 0 Heavy attack.
They would just stay there looking at each other forever and this is not what happens.

People like to say CA´s are "immune" because they assume they are gonna win the screen battle and stay protected by their own CL´s and DD´s.
but wishing =/= from reality.

Is it accurate that screening ships' AA does nothing? My understanding is that a ship's AA is a function of its own AA rating and the fleet average AA (I think it was weighted at 20%). That is, there's a penalty to capital ships' AA capability if the DD and CL aren't equipped with AA, even if the screens themselves aren't targeted.

For naval AA. 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%)

 

[walt526]

Oh okay. So what matters is total AA points in the task force, not the AA average. Thanks for the clarification.

 

[sterrius]

Oh okay. So what matters is total AA points in the task force, not the AA average. Thanks for the clarification.

Also to clarify. The fleet is not penalized for being small.

For example.

1 lone Ship with 10 AA

(( 10 + 10 * 0.2 )^0.2) * 0.15 = 0.245 = 24,5% dmg reduction.

i find that formula quite elegant because it does not penalize the ship for being lonely or in group.
but does penalize a bad configuration ^^.

 

[Razgriz13]

There is a few things not said here:
Individual AA affects 2 things: Preventing to be a target and reduce damage
Individual AA DOES matter in air combat. Doesn't matter if you have 200 fleet AA with a 0 AA ship being targeted, you will take more damage than other ships.
Also, planes have a modifier to attack ships with lower AA. Ships start aiming carriers, then capitals then screens +/-.

 

[Caeric]

A light cruiser can hit a heavy cruiser if there is no Screens.
A Destroyer can do that too.

and if you put a 1 BAttleship vs 10 Destroyers they will shoot at each other even if they both lack good attacks.
And a heavy cruiser can hit a light cruiser with its heavy gun if there is nothing else to shoot.

Otherwise if you put a CA with 0 light attack vs a CL with 0 Heavy attack.
They would just stay there looking at each other forever and this is not what happens.

People like to say CA´s are "immune" because they assume they are gonna win the screen battle and stay protected by their own CL´s and DD´s.
but wishing =/= from reality.






For naval AA. 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%)

I was talking purely based on a historical perspective, an 8" gun didn't offer enough of an advantage over their 6" armed counterparts to offset the much higher volume of fire from a 6" gun. In a pure 1v1 battle the odds of winning swung in favor of a light cruiser after the first minute of engagement as A) a 4-6"/100-152mm belt armor didn't offer much more protection vs a 6" shell than an 8" one. And B) with a light cruiser having around 25+% more guns per salvo as well as firing 25+% faster, the odds of scoring the first decisive hit are simply higher. A ship doesn't even need to be sunk to be rendered incapable of continuing to fight.

 

[SigurdStormhand]

I was talking purely based on a historical perspective, an 8" gun didn't offer enough of an advantage over their 6" armed counterparts to offset the much higher volume of fire from a 6" gun. In a pure 1v1 battle the odds of winning swung in favor of a light cruiser after the first minute of engagement as A) a 4-6"/100-152mm belt armor didn't offer much more protection vs a 6" shell than an 8" one. And B) with a light cruiser having around 25+% more guns per salvo as well as firing 25+% faster, the odds of scoring the first decisive hit are simply higher. A ship doesn't even need to be sunk to be rendered incapable of continuing to fight.

The thing is, most war-time heavy cruisers had inadequate armour - no British cruiser, heavy or otherwise, got above the level of the Town Class, which is Armour II in-game.

 

[Caeric]

The thing is, most war-time heavy cruisers had inadequate armour - no British cruiser, heavy or otherwise, got above the level of the Town Class, which is Armour II in-game.

Not only that but even after the treaty restrictions, few went above 6" belt armor. Even that won't prevent a salvo wrecking fire directors and starting fires and thus making fighting off your opponent near impossible.

 

[Secret Master]

I keep seeing people say that ships with better armor than penetration from enemy fire are "immune" to enemy fire.

Don't think that way. It's a huge mistake.

First of all, critical hits are still possible even when an enemy shot does not pierce. Having better armor than penetration will lower that chance, and damage control techs can mitigate it further, but ship reliability is also a big factor. And when I say critical hits are possible, I'm not talking about being a few points under the armor. I'm talking about Tier 1 DD guns hitting the freaking Yamato. Each individual shot may have a low chance to cause a critical hit, but I've done tests where the worst possible WW1 DDs with the worst guns repeatedly bombard battleships, and in all cases there were some critical hits.

That's not the funny part, though.

The funny part is that critical hits have their full impact no matter what type of gun is used. So, I've seen the worst DDs with the worst guns take out main batteries on battleships, start fires on battleships, damage the rubber on battleships, destroy the freaking screws on a battleship killing its speed, and even hit the magazine. No torpedoes required or used.

These critical hits are not going to sink battleships on their own, but they can effectively cripple one so other ships can finish it off.

I'm not saying that you should spam crappy ships with bad guns to swarm the enemy. But I am saying that if you think your Yamatos are immune to destroyer gunfire, think again. No matter how good your armor is compared to enemy gunfire, you damn well better have decent reliability on your ships and damage control techs in place. Otherwise, your larger ships are vulnerable.

 

[walt526]

The large reliability penalty why I don't use upgraded fire controls (which don't increase piercing, which is more important than a little bit more heavy/light attack, IMHO). Ships with maxed out damage control and no upgrade fire control aren't immune to critical hits, but they are far rarer.

 

[bitmode]

which don't increase piercing, which is more important than a little bit more heavy/light attack, IMHO

Piercing is usually not more important in my opinion.
Over-piercing the enemy has no advantage so against lighter targets increasing piercing is completely wasted.
And against harder targets, the effect from increased damage is still usually stronger. Example versus 25 armor:

• 20 attack, 20 piercing: 20 * (10% + 90% * 20/25) = 16.4
• 20 attack, 22 piercing: 20 * (10% + 90% * 22/25) = 17.84
• 22 attack, 20 piercing: 22 * (10% + 90% * 20/25) = 18.04

If the piercing increase happens to hit the sweet spot where it starts to exceed armor, you'll get a moderate (not crazy) damage increase from the jump in critical hits but against a mixed fleet, depending on admirals etc. this is very unpredictable. An increase in damage will always be useful.

Although - out of all modules - reducing reliability with fire control probably makes the least sense, the effect is not as large as you might think. If I'm not mistaken, a ship with MtG can at most have 64% reliability as a base line, so fire control 3 increases the unreliability (100%-reliability) by at most 18%. Critical hits are accordingly more likely by the same percentage. Even if all damage came from just critical hits (which is far from the truth), the increase in incoming damage would still be lower than the damage bonus fire control provides.

 

[sterrius]

The large reliability penalty why I don't use upgraded fire controls (which don't increase piercing, which is more important than a little bit more heavy/light attack, IMHO). Ships with maxed out damage control and no upgrade fire control aren't immune to critical hits, but they are far rarer.

fire control is not a automatic upgrade no matter what but does have uses and can hugely benefit a ship.

In DD`s for example 90% of the DD´s in the game will have 40hp (DDII) or 50hp (DIII). They don´t survive much hits so having high or low reliability is not a huge issue for a ship that is always gonna die in 1-3 hits anyway. BEtter get that AA bonus they give so you can better protect your capitals or even a little bit more of damage.

Cruisers start to have some HP but they also have a good amount of passive reliability so trading extra dmg for reliability might not be a bad idea if it helps you reaching the key damage thresholds.

For example, if that firecontrol put your ship above 20 Light attack. It can be the difference beetween having to hit 2 times a DD vs hitting him 3 times. Its huge in a battle where we have only 5-10% hit chance each hour.

Later in the game (42+) you want cruisers that can hit 25dmg/hit. and a combination of Research + Firecontrol can put you there instead of just adding more guns to the ship.

Same things for BB. Fire control it might be worth to lose some reliability if it means in the end to kill the enemy sooner. (i don´t remember BB and BC HP right now, but you do need to see how many normal hits it will take to sink your opponent) .

But i agree the firecontrol IV and III are difficulty to use because its not uncommom for you to reach the "sweet spot" for damage using other means.

 

[Secret Master]

the effect is not as large as you might think.

It's worth mentioning that against light ships (subs, DDs and weak CLs), critical hits don't have much impact.

In many cases, these ships tend to die if hit enough times to reliably proc a critical hit. If you don't believe me, ask yourself when was the last time you saw a critical hit on any ships of these types?

Thus, when designing these ships, I don't even bother looking at the reliability stat. And if I'm just spamming subs, I don't even bother with damage control techs. My subs sure as Hell aren't dying because of critical hits.

 

[sterrius]

The main thing about Hit chance vs Critical is that we need to remind outselves its pretty hard to hit a ship in first place.
Usually is around a 5-15% hit chance.
Only after making this you can hope to get a 10 or 20% chance of crit.

Usually a much better way to kill the enemy is just to increase the total dmg.
For example.

Submarines HP 10-20-30-35
Depthy charge dmg 8-12-16-20

how many hits to kill (8-12-16-20 order)
1918sub -> 2-1-1-1
1936-> 3-2-2-1
1940 -> 4-3-2-2
1944-> 5-3-3-2

As we can see upgrading to SUb III is a huge survival increase giving it more time to fire torpedos or flee.

Destroyers
DD HP - > 25-40-50-60
Recommended light attack on cruisers and BB´s -> 20 (1936)-25 (1940)-30 (1942+)
This allows to always two Shot a DD.

Germany and italy might aim for 25 Light attack already in 36 as England have a ton of DD1.


Light CruisersHP -> 120-130-140-150 (+5%-10%-15% from armor II, III or IV)
As we can armor can really make your Cruiser survive +1Hit and that means the enemy need to waste usually +6-7hours trying to hit you.
being able to survive +1hit usually > having +1-3 knots.

Heavy Cruiser HP (With 1 Heavy and 1 Light gun, Yes they do Stack!) -> 168 - 182 - 196 - 210 (+5%-10%-15% from armor II, III or IV)
Remember now its heavy attack at play.
For CA´s i really don´t recommend going above 2 heavy guns as they increase surface detection too much. So your HeavyDmg is limited to +10-30 based on tech.
Armor again can have a great impact on how much you can survive.

Battlecruisers and Battleships HP (With armor I) -> 367.5 - 388.5 - 420 - 472,5
The difference beetween a BB with 20-30 attack and one with 40-60 attack can be quite big even if the slower one usually get hit more often.
BB´s are limited to 2-4 guns to stay above 25-30knots but they can still get firecontrol and radar and the bonus is impressive if you stack them with the bullet research for heavy guns. (+10% for 100 days of research).


In the end critical hits are fine and can change a battle as a critical can add a debuff to your big ship.
But don´t count on them, go for normal hits + Piercing. As those two you can actually control.

 

[totalkrieg]

Most people here seem to be not aware gazzillion stuff buffing armor, including admirals' defence stat which I recently became aware of. Tier I armor will make your cruisers immune to destroyers so never skimp on that. Tier II enough to witstand Tier 4 Light Cruiser battery + 2 light piercing ammo upgrades. On paper Tier II cruiser armor is 8 points while aforementioned ultimate light cruiser armament can barely reach 10 piercing but if you put that tier II cruiser armor ship in an actual fleet with 4-5 defence skill admiral, it'll easily exceed 10 armor alongside a good chief of navy. Overall armor is a lot harder to pierce than most think. Just checked by British save game and my tier 1 BB's with tier 1 armor has 32.9 armor as of now instead of base value of 26. My light cruisers with tier 2 armor has 10.1 armor instead of 8. Mind you this is without any armor buffing ministers as I have pasific fleet designer (designers only effect newly reserched ships though) and carrier specialist navy chief. If UK had a good decisive battle navy chief my tier I BB's would be invulnerable to tier II BB's but they'll be anyway thanks to 10 percent capital ship armor on the doctrine tree.

 

[Secret Master]

Most people here seem to be not aware gazzillion stuff buffing armor, including admirals' defence stat which I recently became aware of.

But they are also overlooking the things that boost penetration, including all of the ammunition techs for light, medium, and heavy guns, not to mention ship designers.

 

[Voigt]

You also lose speed with armour and also increase production cost. Would be interesting how worth Cruiser Armour really is.
For newly built ships I normally still but the hightest tier armour on them as I have, but very rarely do I research new armour types.

 

[totalkrieg]

Tier I cruiser armor is essential for protection against destroyers and Tier II is enough for Tier IV Light Batteries but Tier III and IV cruiser armors are a waste of time. As for cost wise it's better to have 2 very good ships than 3 mediocre ones. My new battleship designs fall between 12k-13k production cost. I refit all of them because of the aforementioned reasons. I refit them with new all 1940 model radars, aa and firecontrol (all tier 3's) and add/replace useless equipment with dual purpose secondary armaments. I pay around 1900-2500 production cost for refit of each battleship but it's well worth. Because before the refit, They usually have around 25-30 heavy attack, 6-8 light attack and 1-2 AA. With refit heavy attack nearly reaches 40s, light attack around 25-30 and AA to 20-25. These battleships currently kill 30 aircraft en masse repeatedly.