Downfall - Revised

[PaxMondo]

I've been working on revising the Downfall scenario. It is one of my favorites as I like testing end of war defense. My issue with the scenario as written is that everything is so far from how I play IJ that I have to spend the first week of turns just getting things organized.

I'm not the scenario designer (I believe Andy Mac is, at least he is listed as the author) so I'll be trying to make changes within the context of the scenario design as I see it. So, without changing the overall unit base of IJ, I'm making some rather extensive changes to where things are. IJ will still be in a precarious position of course, but a lot of things will be better aligned. Once I'm done with the IJ, I'll do the same for the allies. I think it will be better balanced for a PBEM game. I'll likely have to make "Ironman" versions for AI play. The stock scenario playing IJ on VH is a pretty good challenge as you so out of position that it is really tough.

Anyway, I'm working through this and I thought others might like this as well so I will be posting the revision here as Scen 50. You can, of course, re-number as you wish.

Scenario Design Analysis
The overall scenario starts with the end of the Okinawa campaign, following the historical path of Marianas->PI->Iwo Jima->Okinawa. The map is shortened to exclude Soviets, so all of the IJ forces for them need to be left out. It is also shortened to exclude CHI, so again a large number of units need to be held out. Singers was taken by amphib assault on the Malay peninsula so that IJ still controls Bangkok and all points east to Shanghai. Forces in China are isolated from Korea. Interpret that this is due to CHI/SOV forces having joined and blocking migration on map.
Almost all IJ forces are disorganized with high disablements, low % TOE, and low experience. The interpretation is that an all out defense for Okinawa was made and failed. Primary reaction forces are missing, so assumed that they were also consumed in the carnage of Okinawa.

IJ Strategy Considerations
Bases
At this point, all bases will be in their final point in terms of build up. In the inner perimeter, which is most of the map, an IJ player would have built the AF's up to maximize defense. Forts would also be final, with minimum of 3, max of 6 on coastal hexes. Tokyo/Osaka and a few other key industrial bases will be Fort level 9 to minimize night bombing damage.
Fort Criteria: Fort level = MIN(ROUNDDOWN(3+(TotalNumberFactories)/150,0),9). If it is a coastal base in the HI, then minimum fort level is 6 not 3. "Hideaway" ports will get Fort level 9 to protect ships disbanded (sub pens).
Airfield Criteria: Lvl 9 where possible on all RR line bases to get AV bonus.
Port Criteria: Tokyo built up to allow for CS conversion. Fusan/Ominato/Hakodate/Wakkanai/Sakura built up to max for resource flow. Niigata/???/???/??? built up as "hideaway"/"sub pen" ports. Otherwise port sizes will be left as 1941 start.
(???) need to be identified, I haven't decided whether to post them here or leave them for you to discover in the editor.

Aircraft
This is PDU ON. For PDU OFF, just play the stock version. [;)]
Sorry, I just can't wrap my head around flying Nates in '45.

[PaxMondo]

IJ Aircraft
First pass to come up with final production models. The list of production models was severely pruned from stock. This pass assumes that 3rd Gen AC are pursued. A future version may be done where RnD stops with 2nd gen AC.

Then starting from 12/7/41 a model progression path was developed. This progression was then laid over the AC factories using typical factory sizes resulting from RnD (30). Start dates of models were adjusted also based upon the progression model to help determine total production numbers of each model. For obsolete models, this would be the basis for pools (based upon number of groups that were available at time of upgrade and max pool sizes that players generally carry in early/mid war timeframes)


Air groups
Given production numbers of late war final models and start date, air group compositions are determined (minus losses).
Many sunken CV air groups are missing. Needs review. Will be interpreted that these units are used in defense in CHI/SOV areas.
Air groups dedicated for pilot training are identified based upon typical player criteria, composed of older model aircraft and low exp pilots that are being trained. Training air groups are sequestered away at backwater lvl 9 AF.
Best pilots are pooled into air groups with best aircraft. Best remaining fighter pilots are in defensive squadrons and NF's.

[PaxMondo]

For IJ Production
9/45 - given premise that 2nd Gen AC were not overbuilt as evidenced by the pools, there should be good pools of all key items for the IJ to fight for 12 months. At this point fuel should be running low, HI turned off to conserve fuel, and the economy running on ample HI reserves.
ARM - 500,000K, VEH 150,000K both still building.
LI running flat out, HI 70% shut down to conserve fuel for IJN. NSY/MSY running low ~25%.
HI - 3,000,000 in bank. Sufficient to build


Leaders
Need to ensure that expected losses are reflected in list
Probability of loss based upon start date
All units will have had best possible leaders put in place.

[PaxMondo]

For IJ Ships
Most ships should be upgraded to current class. In most cases this will be final class.
Shipping should be disbanded in "hideaway"/"sub pen" ports
Damaged ships in repair????
MSY should have large number of ships NOT built … hold at <5 days build time.
NSY will have fairly large number being built late as CV's would have been accelerated.

[PaxMondo]

For IJ LCU's
Units should all be upgraded to current TOE
- if current month, no upgrade has occurred.
Devices should all be upgraded to current model
- if current month, no upgrade has occurred.
- Upgrade probability = # days since upgrade available*(build rate/(total device usage)). => last month only 30%* *(build rate/(total device usage)) probablilly that device has been upgraded. So for radar upgraded, this will be quite small ~1% chance for each radar. After a year, a much higher probability.
- if > (current month -2) , upgrade probability = 100 *(build rate/(total device usage)). => 100*(build rate/(total device usage)) probablilly that device has been upgraded. So for radar upgraded, this will be quite small ~1% chance for each radar.
Sub units should all be aggregated into parent unit where possible.
Most units should be fully prepped for their location.

LCU Location
- original scenario had removed all "restricted" HQ's. Agree with that design as it represents that by this time, enough PP's have accumulated to allow any unit to move anywhere. Removing the restriction just makes setup easier.
- Getting reasonable garrisons setup on all Japan islands, particularly Kuriles and Hokkaido.
- in general, no changes made to unit disruption values to represent the outcomes of the Okinawa inferno.

Devices
Reviewed and corrected obvious errors:
Set Buildable, but no rate entered. Criteria: If represent captured allied device, then not buildable. Otherwise add minimal build rate, typically 1/month. Review Scen #1.
Set not buildable, but rate entered. Criteria: If represent captured allied device, then not buildable and set rate to 0. Otherwise switch build flag to 'on' for rate entered. Review Scen 1.
Device Upgrade Model has been set for ALL device. (needs to be uploaded into scenario)
Device pools should reflect late war .. .. Pools should exist for ALL devices except as detailed below.
Pool exception list:

Pool determination criteria:
If device is >6 months obsolete, pool will be 12 month run rate OR 500 max
If device is <6 months obsolete, pool will be obsolete months * 2 run rate OR 500 max.
If device is NOT obsolete, pool will be monthly run rate / 2.
Where no monthly run rate is set, then MIN(substitute total device usage/100,10) for the run rate.

[PaxMondo]

For Allied Air

[PaxMondo]

For Allied Ships

[PaxMondo]

For Allied LCU's

[PaxMondo]

For final wrap-up

[PaxMondo]

Spare

[Andy Mac]

Sounds good look forward to playing it

[Lowpe]

Playing as Allies, I know that their recon training and amount of recon planes really hurts early on.

Not to mention the B29 squadrons for the most part are commanded by dogs.

Great news.[&o]

[spence]

My father was preparing to deploy to the Pacific with VB-126 when the war ended with IJ's surrender. He flew PV-1s in the Atlantic but the squadron was supposed to re-equip with PV-2s. For the Downfall Scenario there ought to be a whole bunch of PV-2D's (an attack bomber variant) which had 8 x 50 cals in the nose for use as attack bombers...in the end most of the contract was cancelled because Japan surrendered but IIRC then Navy had contracted for almost 400.

BTW I don't find anything to download...is there supposed to be something to the IJ Air, IJ ships, Allied whatever, postings?

[PaxMondo]

ORIGINAL: Lowpe

Playing as Allies, I know that their recon training and amount of recon planes really hurts early on.

Not to mention the B29 squadrons for the most part are commanded by dogs.

Great news.[&o]

Noted. Commander example is basically what I'm referring to. At this point of the game, most players would have spent the PP's to get good commanders in charge of key assets. B-29's would qualify for me.

[PaxMondo]

ORIGINAL: spence

My father was preparing to deploy to the Pacific with VB-126 when the war ended with IJ's surrender. He flew PV-1s in the Atlantic but the squadron was supposed to re-equip with PV-2s. For the Downfall Scenario there ought to be a whole bunch of PV-2D's (an attack bomber variant) which had 8 x 50 cals in the nose for use as attack bombers...in the end most of the contract was cancelled because Japan surrendered but IIRC then Navy had contracted for almost 400.

BTW I don't find anything to download...is there supposed to be something to the IJ Air, IJ ships, Allied whatever, postings?

If the PV-2D's are in the game, then they will appear.

Place holders will be filled up here over the next couple of weeks.

[PaxMondo]

ORIGINAL: Andy Mac

Sounds good look forward to playing it

You are listed as the author, appreciate any thoughts on my summary/interpretations on the scenario.

[RyanCrierie]

Do you want a copy of W-15, the US aircraft production schedule for 1945-46 which was finalized in the Summer of 1945, but cancelled in August?

[PaxMondo]

ORIGINAL: RyanCrierie

Do you want a copy of W-15, the US aircraft production schedule for 1945-46 which was finalized in the Summer of 1945, but cancelled in August?

Sure, that would be interesting ...

[RyanCrierie]

PM(s) sent.

[PaxMondo]

Rcvd. THANKS!!! very interesting reading.

I'm very close to wrapping up the IJ side. Then I start working the same issues on the allied side.