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HoI4 Dev Diary - The Imperial Japanese Navy (AAR)

Hello, and welcome back to another Dev Diary from the frozen wasteland that is Sweden in January. Today, we will have another short AAR of a naval warfare scenario, similar to the one we did earlier about raiding and submarine warfare.


This was played as an MP game between me and Niall (@Ceebie), with me defending the Empire of Japan’s honor against Niall’s filthy American imperialists.


Starting as Japan, I immediately face a number of issues that should sound very familiar: I have very limited resources, particularly in terms of oil. This is now a much bigger issue as I can still happily build ships and airplanes and tanks, but I won’t be able to run them for free. However, if I want to upgrade my ships (and knowing Niall, I absolutely do), I will need naval experience, and China is unlikely to provide me with a lot of it. So I need to run training missions for my fleet, which gobbles up fuel at a rapid pace (I could only take out my main fleet units for a few brief weeks before the fuel situation became critical).


Screenshot_2.jpg



At the same time, while I could trade for more oil, it will cost civilian factories which I desperately need to build up my own industry or to trade for steel to continue my military buildup. I decided to keep the trading for oil to a minimum in order to more quickly build up my industry and increase the size of my fleet.


Screenshot_4.jpg


My first target is, of course, China, and we start the war with them in the middle of 1937. It quickly becomes apparent that I underestimate the Chinese. Fighting rages hard along the border for several weeks, and a number of naval landings that attempt to force the AI to draw troops away from the main front are quickly contained by local garrisons, but at least not pushed back into the sea. Part of the problem is that the fleets tasked with invasion support contain some of my battleships, which eat up absurd amounts of fuel, and my attempts to turn the tide through prolific use of air support eat into my fuel supplies even more.


By early 1938, we are slowly grinding forward and have managed to inflict serious casualties on the Chinese, but my fuel stockpile has shrunken to just 30 days of current use. I curtail air support to only support my main thrust and send the naval forces providing shore bombardment back to port. Progress slows, but eventually we link up with the landing forces, at least saving me from an embarrassing early defeat. The massive amounts of Land XP also allow me to run through the doctrine tree quite a bit faster than Niall could ever hope to. Sadly the war in the Pacific will not be fought on land.


Screenshot_5.jpg



It would take until early 1941 for the Chinese to fall, even though the writing is on the wall by the middle of 1940. I blame the poor infrastructure and awful terrain in China - my leadership is, after all, beyond any reasonable doubt.


In the meantime, Niall has been quietly modernizing his fleet and has started his rearmament. While a good amount of his effort is spent on helping out the British in Europe, I have no doubt that he has something in store for me. While I was deeply engaged in managing the war in China, I received some out-of-game intelligence (Niall bragging in the kitchen that his destroyer swarms would annihilate me) that makes me realize that my fleet lacks some key capabilities. The starting Japanese light cruisers are fairly mediocre, most have been built during the 20ies and are not up to the task of winning a firefight against the likes of a Brooklyn Class cruiser with no less than 3 light cruiser battery modules. What I do have is a lot of torpedoes, and I invest a little into researching upgraded torpedoes and better launchers. The Japanese Long Lance national spirit gives me another perk, as it negates the enemy screening to an extend, which means that my torpedoes can hit his capitals even through 100% screening.


Screenshot_1.jpg



So while I was slowly grinding my way across China, I also decided on my buildup strategy:


  • No new battleships, since they eat up a lot of fuel and I have enough to cover my carriers. However, I did later decide to build at least one Yamato-class as an insurance against Niall developing modern battleships.

  • A force of 4 light carriers. Japan starts with two (Ryujo and returning fan favourite Hosho), with two Zuhio class building. While these only carry 40 planes each, they will be used to provide cover for operations in and around the Dutch East Indies.

  • A force of 4 fleet carriers, with another force of 4 joining later. Akagi and Kaga will be joined by 2 more Soryu class carriers and form the main strike force in the Central Pacific.

  • A heavy emphasis on air defense and torpedoes. After researching dual purpose main armaments, I design a new destroyer class with improved AA and better torpedo armament. These are joined by a quartet of light torpedo cruisers from the Japanese focus.

  • Lots and lots of Naval Bombers to damage the enemy during the approach and pick off stragglers. Once the battle is fought, his damaged ships would likely try and find a close naval base for repairs, so having naval bombers ready to attack them in port would let me finish them off.

  • Once I identified the fleet’s weakness in defense against destroyers, I also designed a version of the Mogami Class heavy cruisers dedicated to light gun support. I built another 4 of these.

Screenshot_6.jpg

The fleet’s main objective, however, is to provide support for landings to seize resource rich areas in the Dutch East Indies. To protect the sea lanes to and from these islands, I will need to secure the Philippines, and that is where things get a little dicey.


While I have little doubt that my forces can take over Sumatra, Java and Borneo, Malaya might be a tough nut to crack, and I know that Niall has already started to fortify the Philippines. I have researched amphibious armor well in advance and with China now pacified, I start to turn up production in an attempt to give my marines a bit more punch and hopefully allow me to seize a foothold even against heavy opposition.

Screenshot_16.jpg

Thinking ahead, I also research improved naval bombers and the next generation of carrier planes. Once my main objectives are secured, I will use swarms of naval bombers to hold them down while I move my fleets to stage two and take on Australia.


To give myself some more time to buildup, I delay my attack on the US until early 1942. This allows me to form a second strike force of two fleet carriers (Shokaku and Zuikaku, both repeat Soryus as I was unable to scrape together enough XP to design an upgraded carrier).


The first battles are very encouraging. Whenever my patrols find one of his scouting units, my strike fleets sortie and make short work of them, Niall’s vaunted Destroyer swarms being no match for my upgraded cruisers and destroyers. I am somewhat confident that I can attrit his screening forces faster than he can replace them, which would eventually force his fleet to remain in port or eat absurd numbers of torpedoes.

Screenshot_11.jpg


Things quickly turn a little chaotic as my strike fleets and patrols intercept a number of troop convoys. While I first thought that these were going to the Philippines, they instead turn out to be trying to seize islands in the Central Pacific. Things don’t go well for him, as he has decided to keep his battleships and carriers on strike duty instead of covering his invasion convoys. Several divisions are effectively destroyed at sea, and the remains fail to gain any footholds.


At the same time, my invasions in the DEI, supported by the old battleships Ise and Hyuga, have run into stiff opposition while attempting to land in Borneo. I shift some tactical bombers into the theater to help break the stalemate, and we are starting to make progress. The two-pronged assault succeeds in establishing a foothold, but it is a reminder that Niall has not been idle and is ready to fight for every inch of ground in this vital area.

Screenshot_13.jpg


While my marines still struggle to make landfall in the Philippines, a bigger drama unfolds in the Bismarck Sea. Niall has finally unleashed his main strike force, after one of his patrols found my carrier fleet.


The Battle of the Bismarck Sea does not go particularly well for the Imperial Navy. With several battleships detached for minor repairs, the US Navy breaks through my screening units and manages to do an end run on my carriers, sinking all four for no capital ship loses on their side. The survivors straggle home, many ships badly damaged during the ferocious engagement as my battle line attempted to screen against the full might of the US battlefleet.

Screenshot_8.jpg

However, Niall’s victory has come at a steep cost. Most of his battlefleet is badly damaged, and he has nothing to follow his success up with. More than that, I still have 6 carriers in reserve (2 fleet, 4 light), and several hundred naval bombers scouring the Bismarck Sea means that he has to risk his battleships again to sail them to safer harbours for repairs. Several of them take further damage as they retreat, many of them out of the battle for almost a year.

Screenshot_15.jpg

While Niall has blunted my offensive power quite severely, he has nothing to interfere with in my operations in the DEI, which were the main objective. Trying to use the Philippines as an unsinkable aircraft carrier has become next to impossible as trying to supply it with fuel would cost him too many convoys and tank his war support. The Japanese conquest of the southern resource area won’t quite be the lightning strike it was in history, but it is as inevitable as the rising of the sun.

Screenshot_14.jpg

With hindsight, my performance in the naval war thus far comes down to:

  • Lack of radar allowing Niall to get the drop on me in a critical moment

  • Lack of training due to fuel concerns

  • Insufficient coverage of the seazones with naval bombers failing to disrupt the enemy on the approach

  • Not enough screening vessels to protect my carriers against his battle fleet. Although Yamato sunk several ships and survived to fight another day, spending the same amount of 3 heavy cruisers would likely have yielded better results

  • Good performance of my light forces when engaged on equal terms

That is all for today. Tune in at 1600 CET for another stream with an indepth look at fuel.
 
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Thats all you got for us, after one week of waiting for a new Dev Diary? THis ain't a DD it is a report in how someone made a battle! When i read the title i hoped for some changes for the Japanese Navy, that come with the update or DLC, but nope.
And not even a release date, but thats somehow second, if you at least show me more stuff, thats coming out! And even the streams got lamer. Instead of showing us the new nations on different paths and showing of the fuel stuff, you just go to old countries and do only fuel. Be more creative than that!

Some changes for Japan include the revised Long Lance focus, which allows greater chances of attacking enemy main fleets even with screens around.

Kidding aside, I agree that as the 3rd largest navy at that time, Japan deserves a few naval perks at least. However, I think the DD's main focus is more on showing the new naval mechanics combined with the realities of fuel consumption. With those two in mind, the devs showing us an AAR about the IJN makes perfect sense.

In the end though, yeah. I personally hope Japan gets some new stuff too. Not as much as USA or UK, but enough to reference the IJN's power back then. Still a good DD. :)
 
It would nice to see some serious gameplay on stream to show the realities of fuel. For example, to see how deprived can Germany be during Barbarossa for example.

But it is nice to hear from the devs that at the very least Japan will not be able to spam aircraft and will have suply problems in China
 
Hello, and welcome back to another Dev Diary from the frozen wasteland that is Sweden in January. Today, we will have another short AAR of a naval warfare scenario, similar to the one we did earlier about raiding and submarine warfare.


This was played as an MP game between me and Niall (@Ceebie), with me defending the Empire of Japan’s honor against Niall’s filthy American imperialists.


Starting as Japan, I immediately face a number of issues that should sound very familiar: I have very limited resources, particularly in terms of oil. This is now a much bigger issue as I can still happily build ships and airplanes and tanks, but I won’t be able to run them for free. However, if I want to upgrade my ships (and knowing Niall, I absolutely do), I will need naval experience, and China is unlikely to provide me with a lot of it. So I need to run training missions for my fleet, which gobbles up fuel at a rapid pace (I could only take out my main fleet units for a few brief weeks before the fuel situation became critical).


View attachment 446333


At the same time, while I could trade for more oil, it will cost civilian factories which I desperately need to build up my own industry or to trade for steel to continue my military buildup. I decided to keep the trading for oil to a minimum in order to more quickly build up my industry and increase the size of my fleet.


View attachment 446334

My first target is, of course, China, and we start the war with them in the middle of 1937. It quickly becomes apparent that I underestimate the Chinese. Fighting rages hard along the border for several weeks, and a number of naval landings that attempt to force the AI to draw troops away from the main front are quickly contained by local garrisons, but at least not pushed back into the sea. Part of the problem is that the fleets tasked with invasion support contain some of my battleships, which eat up absurd amounts of fuel, and my attempts to turn the tide through prolific use of air support eat into my fuel supplies even more.


By early 1938, we are slowly grinding forward and have managed to inflict serious casualties on the Chinese, but my fuel stockpile has shrunken to just 30 days of current use. I curtail air support to only support my main thrust and send the naval forces providing shore bombardment back to port. Progress slows, but eventually we link up with the landing forces, at least saving me from an embarrassing early defeat. The massive amounts of Land XP also allow me to run through the doctrine tree quite a bit faster than Niall could ever hope to. Sadly the war in the Pacific will not be fought on land.


View attachment 446335


It would take until early 1941 for the Chinese to fall, even though the writing is on the wall by the middle of 1940. I blame the poor infrastructure and awful terrain in China - my leadership is, after all, beyond any reasonable doubt.


In the meantime, Niall has been quietly modernizing his fleet and has started his rearmament. While a good amount of his effort is spent on helping out the British in Europe, I have no doubt that he has something in store for me. While I was deeply engaged in managing the war in China, I received some out-of-game intelligence (Niall bragging in the kitchen that his destroyer swarms would annihilate me) that makes me realize that my fleet lacks some key capabilities. The starting Japanese light cruisers are fairly mediocre, most have been built during the 20ies and are not up to the task of winning a firefight against the likes of a Brooklyn Class cruiser with no less than 3 light cruiser battery modules. What I do have is a lot of torpedoes, and I invest a little into researching upgraded torpedoes and better launchers. The Japanese Long Lance national spirit gives me another perk, as it negates the enemy screening to an extend, which means that my torpedoes can hit his capitals even through 100% screening.


View attachment 446336


So while I was slowly grinding my way across China, I also decided on my buildup strategy:


  • No new battleships, since they eat up a lot of fuel and I have enough to cover my carriers. However, I did later decide to build at least one Yamato-class as an insurance against Niall developing modern battleships.

  • A force of 4 light carriers. Japan starts with two (Ryujo and returning fan favourite Hosho), with two Zuhio class building. While these only carry 40 planes each, they will be used to provide cover for operations in and around the Dutch East Indies.

  • A force of 4 fleet carriers, with another force of 4 joining later. Akagi and Kaga will be joined by 2 more Soryu class carriers and form the main strike force in the Central Pacific.

  • A heavy emphasis on air defense and torpedoes. After researching dual purpose main armaments, I design a new destroyer class with improved AA and better torpedo armament. These are joined by a quartet of light torpedo cruisers from the Japanese focus.

  • Lots and lots of Naval Bombers to damage the enemy during the approach and pick off stragglers. Once the battle is fought, his damaged ships would likely try and find a close naval base for repairs, so having naval bombers ready to attack them in port would let me finish them off.

  • Once I identified the fleet’s weakness in defense against destroyers, I also designed a version of the Mogami Class heavy cruisers dedicated to light gun support. I built another 4 of these.

View attachment 446337
The fleet’s main objective, however, is to provide support for landings to seize resource rich areas in the Dutch East Indies. To protect the sea lanes to and from these islands, I will need to secure the Philippines, and that is where things get a little dicey.


While I have little doubt that my forces can take over Sumatra, Java and Borneo, Malaya might be a tough nut to crack, and I know that Niall has already started to fortify the Philippines. I have researched amphibious armor well in advance and with China now pacified, I start to turn up production in an attempt to give my marines a bit more punch and hopefully allow me to seize a foothold even against heavy opposition.

View attachment 446339
Thinking ahead, I also research improved naval bombers and the next generation of carrier planes. Once my main objectives are secured, I will use swarms of naval bombers to hold them down while I move my fleets to stage two and take on Australia.


To give myself some more time to buildup, I delay my attack on the US until early 1942. This allows me to form a second strike force of two fleet carriers (Shokaku and Zuikaku, both repeat Soryus as I was unable to scrape together enough XP to design an upgraded carrier).


The first battles are very encouraging. Whenever my patrols find one of his scouting units, my strike fleets sortie and make short work of them, Niall’s vaunted Destroyer swarms being no match for my upgraded cruisers and destroyers. I am somewhat confident that I can attrit his screening forces faster than he can replace them, which would eventually force his fleet to remain in port or eat absurd numbers of torpedoes.

View attachment 446340

Things quickly turn a little chaotic as my strike fleets and patrols intercept a number of troop convoys. While I first thought that these were going to the Philippines, they instead turn out to be trying to seize islands in the Central Pacific. Things don’t go well for him, as he has decided to keep his battleships and carriers on strike duty instead of covering his invasion convoys. Several divisions are effectively destroyed at sea, and the remains fail to gain any footholds.


At the same time, my invasions in the DEI, supported by the old battleships Ise and Hyuga, have run into stiff opposition while attempting to land in Borneo. I shift some tactical bombers into the theater to help break the stalemate, and we are starting to make progress. The two-pronged assault succeeds in establishing a foothold, but it is a reminder that Niall has not been idle and is ready to fight for every inch of ground in this vital area.

View attachment 446341

While my marines still struggle to make landfall in the Philippines, a bigger drama unfolds in the Bismarck Sea. Niall has finally unleashed his main strike force, after one of his patrols found my carrier fleet.


The Battle of the Bismarck Sea does not go particularly well for the Imperial Navy. With several battleships detached for minor repairs, the US Navy breaks through my screening units and manages to do an end run on my carriers, sinking all four for no capital ship loses on their side. The survivors straggle home, many ships badly damaged during the ferocious engagement as my battle line attempted to screen against the full might of the US battlefleet.

View attachment 446342
However, Niall’s victory has come at a steep cost. Most of his battlefleet is badly damaged, and he has nothing to follow his success up with. More than that, I still have 6 carriers in reserve (2 fleet, 4 light), and several hundred naval bombers scouring the Bismarck Sea means that he has to risk his battleships again to sail them to safer harbours for repairs. Several of them take further damage as they retreat, many of them out of the battle for almost a year.

View attachment 446344
While Niall has blunted my offensive power quite severely, he has nothing to interfere with in my operations in the DEI, which were the main objective. Trying to use the Philippines as an unsinkable aircraft carrier has become next to impossible as trying to supply it with fuel would cost him too many convoys and tank his war support. The Japanese conquest of the southern resource area won’t quite be the lightning strike it was in history, but it is as inevitable as the rising of the sun.

View attachment 446345
With hindsight, my performance in the naval war thus far comes down to:

  • Lack of radar allowing Niall to get the drop on me in a critical moment

  • Lack of training due to fuel concerns

  • Insufficient coverage of the seazones with naval bombers failing to disrupt the enemy on the approach

  • Not enough screening vessels to protect my carriers against his battle fleet. Although Yamato sunk several ships and survived to fight another day, spending the same amount of 3 heavy cruisers would likely have yielded better results

  • Good performance of my light forces when engaged on equal terms

That is all for today. Tune in at 1600 CET for another stream with an indepth look at fuel.
Wait, did you bump the XP cost of rushing research to 100? I thought it was already too expensive at 50. At 100 it becomes a non-option in all but the most XP-rich games. Saving 90 days on research is nice, but there's no way that's worth forgoing engine 5 on your light tanks or armor 5 on mediums.
 
Release date: When it's ready.
 
Wait, did you bump the XP cost of rushing research to 100? I thought it was already too expensive at 50. At 100 it becomes a non-option in all but the most XP-rich games. Saving 90 days on research is nice, but there's no way that's worth forgoing engine 5 on your light tanks or armor 5 on mediums.

It depends on the tech (XP cost). On land doctrines it looks like it can shave about ~160-180 days off. (obviously less if you have already other research bonuses)
 
Very Good Diray. I like it and you can see what you can do and what not. That the Japan-China-War goes 4 to 4,5 Years is realistic enough. I have Hoi4-Games where the Japan-China War is ended in 2 or 2,5 Years.

I like to play that new Versions and DLC´s soon too. But I wanna have a fixed and upgraded Game more than the hasty Reactions with the last 3 middle Patches and DLC´s, which came in a 1/2-year-Rhytm. That ones were nice and bring in new Features and Fixes as well as Focuses, Researches and small Changes for Navy to medium Chances in Army and Airforce.

And for a very very big Feature-, Focuses, Researces and XP-Upgrade as well as new Features and overseen Bugfixes I wait as long as it needs. And the new 3/4-Rythms for big Bugfixes, Changes, Researches and Focuses as well as more Things for Hoi 4 is absolutely well.

And mostly it´s the mater of Fact that in such DLC and Patch-Plans the Devs which are Ready with one thing beginning the next Stage of DLC / Patch-Work. And I could bet that the DLC 1.6.5 / 1.7 is already in the beginning Stage (which beginns with Ideas to upgrade / change that or that, look for the whishes from the Gamers for the next DLC, look for not done main and minor focuses which are important in that timeline; if that Focuses are ready the unimportant will get a small upgrade). Same for the next small / medium Patches and the next big one.

Some of these things will come in in the medium Patches for 1.6 like in the Predecessors. The other things will come in the next big Patch and DLC. But we will see with what the Devs will surprise us in the Upgradepatches for 1.6 and not seen Features in the new DLC.
 
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Has anything been done about the fact that in a PvP situation where you're facing CVs, there's no reason to put anything but fighters on your own CVs? Because if you don't, but the other guy did, your CAGs will get massacred while his CAGs will still continue killing ships as CV FTRs also have a naval attack stat.
 
Very glad to see that the new fuel mechanics have done something to slow down the Sino-Japanese War, but it still ended too fast! You should not be saying it dragged on to 1941 - you still beat the Chinese 4 years before the end of the war!

The war in China should last the entire game - forcing the Japanese to juggle resources between the fight in China and the fights in the Southeast Pacific.
sino japanese war needs a low response mechanic or make a peace deal and get long runs of border clash with nationalist trought at least 2 years and then resume the war.
 
I see "Kitakami Class Torpedo Cruiser" in the screenshots. Is there a tech of "Torpedo Cruiser" that unlocked the model, or you just designed a ship class and named it yourself?
 
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Is the US + allies embargo of Japan going to be factored into the expansion? Like will the US get a focus to give the DEI, British, and French events to embargo Japan of all crucial resources or withdraw from China?
 
Wait, did you bump the XP cost of rushing research to 100? I thought it was already too expensive at 50. At 100 it becomes a non-option in all but the most XP-rich games. Saving 90 days on research is nice, but there's no way that's worth forgoing engine 5 on your light tanks or armor 5 on mediums.

For doctrines it is closer to 180 days. Depends on your situation obviously but generally I find it useful.

I see "Kitakami Class Torpedo Cruiser" in the screenshots. Is there a tech of "Torpedo Cruiser" that unlocked the model, or you just designed a ship class and named it yourself?

The Torpedo Cruiser focus unlocks a special hulltype that has more slots available for torpedoes.
 
I see "Kitakami Class Torpedo Cruiser" in the screenshots. Is there a tech of "Torpedo Cruiser" that unlocked the model, or you just designed a ship class and named it yourself?

Japan gets a focus that unlocks torpedo cruisers as a unique ship class in the current version, I imagine it has been updated accordingly for 1.6/Man the Guns.
 
Very glad to see that the new fuel mechanics have done something to slow down the Sino-Japanese War, but it still ended too fast! You should not be saying it dragged on to 1941 - you still beat the Chinese 4 years before the end of the war!

The war in China should last the entire game - forcing the Japanese to juggle resources between the fight in China and the fights in the Southeast Pacific.

What's worse, he clearly didn't use 14/4s or MOT/LARM to flank the Chinese or AI China would've capped by 1938.
 
I'm a little concerned about the part of the dev diary where you said how you would have several hundred naval bombers watching over the sea. Are you nerfing the impact of kamikazes/naval bombers so they dont just delete any navy that they touch? Or at least increasing the impact of ship aa to counter them.