WITP bomb accuracy

[el cid again]

Should not all bombs have the SAME accuracy?

Why do they vary from values like 4 and 7 to 90?

Ballistics is ballistics - and I don't think a 4000 pound bomb is inherently 22.5 times more accurate than a 50 kg bomb is.

This is a big part of the air ASW problem - bombs are often grossly too likely to hit.

[el cid again]

USAAF data: the chance of destroying a 100 ft x 100 ft (10,000 sq ft) target by a B-24 at 20,000 feet was 1.2 per cent.
It would require 1100 bombers to raise that to 90 per cent chancce.

IJN data: Fujida trained Kates to drop 800 kg bombs at PH. A special vicc of 5 had a 80 per cent chance of one hit (Each plane had one bomb) - or 16 per cent per bomb. This is the most accurate bombing with dumb bombs ever reported.

[spence]

Presumably your figures pertain to horizontal bombing of stationary targets only.

According to Shattered Sword Akagi was attacked by 3 SBDs at Midway (divebombing) which scored 1 hit and 1 near miss. Not sure how one might record a near miss a la WitP (which may well have caused damage resulting in Akagi's rudder subsequently becoming jammed) but in any case the single solid hit by itself would record a hit percentage of 33 percent.

May we all assume that the incredible accuracy reported by Fujita is, conveniently, almost alone a "survivor" amongst all those Japanese records destroyed at the end of the war?

[JeffroK]

Sid , In the past (12 mths +) you claimed that accuracy had some relevance to effect.
 
I think we could go some way to eliminating the 4E bogeyman & the uber Betty by first lowering the accuracy then lowering the effect of bombs and torpedos.

[el cid again]

ORIGINAL: spence

Presumably your figures pertain to horizontal bombing of stationary targets only.

According to Shattered Sword Akagi was attacked by 3 SBDs at Midway (divebombing) which scored 1 hit and 1 near miss. Not sure how one might record a near miss a la WitP (which may well have caused damage resulting in Akagi's rudder subsequently becoming jammed) but in any case the single solid hit by itself would record a hit percentage of 33 percent.

May we all assume that the incredible accuracy reported by Fujita is, conveniently, almost alone a "survivor" amongst all those Japanese records destroyed at the end of the war?

Yes - the base case is horizontal bombing of a non moving target. Dive bombing (and skip bombing and glide bombing make it more accurate; moving targets decrease hit probability). But dive bombing is always significantly more accurate - and for more than one reason. First - a big factor is altitude of bomb release. Dive bombers release at about 2000 feet - while horizontal bombing is several or more often many times that high - the altitude picked for the amount of damage you wish to take from FLAK as a rule. The other thing is that dive bombing permits a different form of aiming - and the target is in the sights of the pilot - who flies a path intended for the bomb to be released from.

No - you may not assume Fujida is making a false report. For one thing - while Fujida developed the tactic - he didn't tell us about it. It was reported by former Zero pilots turned IJN historians in an early Japanese language history (translated into English under the title Zero - a book generally about lessons learned and the mistakes made learning them). And no - you may not assume the records were destroyed. We have a variety of materials on this matter - Pearl Harbor is studied intensely by Japanese academics and Naval officers - and before they got properly started - a US historian named Gorden W Prang went all over Japan with authorization from the Supreme Commander to collect records and record testimony. Much of this material has now been translated and published by the University of Hawaii Press: see The Paarl Harbor Papers, The Pacific War Papers - and a third volume in the series whose name I forget. Further - there is the operational evidence - this is the bombing that blew up USS Arizona - and that under battle conditions. The hit rates reported above were in practice with no hostile fire. There is also a command history: only AFTER this accuracy was reported to admirals was the particular operational plan approved. They were not going to use the Kates in this role UNLESS hits could be guaranteed. [I think the altitude was 25,000 feet. US AA had a fuse set ceiling of 22,600 feet - and at Clark they went in at 25,000 feet for that reason.]

[el cid again]

ORIGINAL: JeffK

Sid , In the past (12 mths +) you claimed that accuracy had some relevance to effect.

I think we could go some way to eliminating the 4E bogeyman & the uber Betty by first lowering the accuracy then lowering the effect of bombs and torpedos.

We already lowered the effect of bombs. I am proposing to lower the accuracy too - more or less agreeing with your proposal before you made it.

It is reported by players who used to experience "uber bombing" that it does NOT happen in RHS.

And we DELIBERATELY did what you suggest - two years ago - with respect to effect. RHS for bombs and shells uses a system based on
square root of shell or bomb size - and sometimes other factors (AP use square root of 2/3 of size) - based on explosive effects theory.
This worked well.

I don't know what you mean by "accuracy has some relevance to effect" - and I did not say that.
But it may be I was explaining something from the manual: for certain guns you can change effect instead of accuracy.
That is - if the accuracy gets too low to work for code - we multiply the accuracy by a K factor and divide effect by the SAME
factor. Since these are applied as a product - the outcome still works.

[el cid again]

In the very detailed Command at Sea system - and also in Harpoon (by the same designers) -
bomb accuracy is NOT related to bomb size. ALL bombs are treated the SAME. You use different tables for
dive bombing and horizontal bombing. You modify things because of this or that. But the SIZE of the bomb
is never a factor until AFTER you learn if you hit: THEN the size is used to figure out damage. But the chance per
bomb dropped is ALWAYS the same in the same conditions no matter what size you drop.

The most applicable is Command at Sea - a WWII simulation - and the base case shows
that at 1000 feet you have a 2 per cent chance of a hit with a stick of 2 bombs. That is, 1 per cent per bomb.

For the impact of altitude (of academic interest only - this is handled by code for us)
a stick of 8 bombs has a 1 per cent chance of ONE hit at 10, 000 feet - or 1/8 of 1 per cent per bomb.

There is a modifier IF Axis aircraft: this amounts to 50 per cent (for low bomb numbers) increase in the hit rate - due to the use
of more than one plane in the run - notes say 2 or 3 planes. So the Fujida case would be more accurate still - because that was 5
all on the same run. Note also that Fjuida was attacking non moving targets bigger than the 10,000 sq foot USAAF standard target -
a battleship is about 100 feet wide and 6 to 8 hundred feet long - so it is a much bigger target. Correcting for a standard target - you
get about 2 per cent chance - and that is not a whole lot better than the 1.2 per cent of USAAF.

For the impact of dive bombing, there is 10 per cent chance of a hit per bomb (with release typically about 2000 feet)
vs the largest target with no speed correction (e.g. stationary). This is linear for a small number of bombs released -
20 per cent for 2, 30 per cent for 3 and 40 per cent for 4 = 10 per cent per bomb in all cases. [As the target shrinks
and / or as the target speed increases, this goes down).

In our data set - which is the CHS one with respect to bomb accuracy - we have very high values for large ALLIED bombs.
Standardizing on a lower number will indeed decrease uber bombing effects when such bombs are used. I hope also they help address the too powerful Air ASW bombing effects.

In addition to checking with Dunnigan (author of How to Make War) and Larry Bond (author of Command at Sea and Harpoon) - I checked with USAF.

[el cid again]

The weapon I want to reduce most of all is the 60 KG bomb or DC. It is set at 7. We have a number of others set at 4 or 5 - and they work. So I say - until we understand the impact better - make ALL bombs 4. We know that value works. This will reduce the standard Japanese ASW weapon by 43 per cent. It will have major impacts on Allied heavy bombers - but we vastly increased the weight of bombs they carry - and their ranges - and I don't have a big problem saying a more realistic accuracy should apply to them.

[Shark7]

I know that Harpoon does in fact have different accuracies for different bombs, but this is based more on the bomb type than bomb size. IE laser guided versus anti-runway versus unguided iron bomb, etc.  Also the 'generation' of the bomb/missile will affect its accuracy.  As a general rule, even in a modern setting with our computer aided aiming, the general purpose iron bomb is still lacking in accuracy.  In the end, your best choice for taking out a target is going to be a laser guided bomb or a missile, while the worst choice is going to be unguided munitions.
 
As far as PH goes, and I am wanting confirmation since I take everything I see on the History Channel with some skepticism, is that at least some of the Kates for the PH attack were actually armed with modified 16" shells from the Nagato and Mutsu.  Is that correct and would it make a difference on the accuracy and hit ratios?

[Iridium]

ORIGINAL: Shark7

As far as PH goes, and I am wanting confirmation since I take everything I see on the History Channel with some skepticism, is that at least some of the Kates for the PH attack were actually armed with modified 16" shells from the Nagato and Mutsu.  Is that correct and would it make a difference on the accuracy and hit ratios?

All 800 Kg 'bombs' Japan used were in fact modified 16" shells. They were fairly decent bomb fabrications. I can't imagine them being any worse than regular dumb bombs, unless whoever was wielding the fins on was drunk...

[el cid again]

ORIGINAL: Shark7

I know that Harpoon does in fact have different accuracies for different bombs, but this is based more on the bomb type than bomb size. IE laser guided versus anti-runway versus unguided iron bomb, etc.  Also the 'generation' of the bomb/missile will affect its accuracy.  As a general rule, even in a modern setting with our computer aided aiming, the general purpose iron bomb is still lacking in accuracy.  In the end, your best choice for taking out a target is going to be a laser guided bomb or a missile, while the worst choice is going to be unguided munitions.

As far as PH goes, and I am wanting confirmation since I take everything I see on the History Channel with some skepticism, is that at least some of the Kates for the PH attack were actually armed with modified 16" shells from the Nagato and Mutsu.  Is that correct and would it make a difference on the accuracy and hit ratios?

I did not just say it is the same: I looked it up. I have Harpoon in its mechanical form - and in all variations - and while I have used it as the foundation for game design for a long time - instead of going from memory - I looked. It has a single bomb accuracy table- and the data tables have no bomb accuracy field in them at all. It gives different lines for different kinds of bomb aiming devices - but in our case only "manual" applies. Further - the different lines apply to broad categories - not to different bomb WEIGHTS or sizes. There is no hint that bomb weight is a factor - and in physics - there is no reason for there to be I can think of (and I am one who used to work at a USAF software integration laboratory as a computer engineer: this is the sort of thing I should have run into if it existed). I sort of agree "this is based more on bomb type than on bomb size" - only it isn't bomb type - but airplane type (that is, how the bombs are sighted) - and that does matter. So does altitude. So does target size. So does target speed. All this we must leave to the code to address. I am interested in a standard input of consistent data - which we then modify ONLY for cause - not because someone wants to skew the game in favor of Allied very heavy bombs.

The history channel is often good - I never watch TV but I know some of its guests - authors and historians.

In this case, Matrix and the history channel and all we know from primary documents agree: 16 inch AP shells were modified for use as bombs and dropped from some of the Kates. The Japanese coult not torpedo all the battleships - because they were moored abreast - in pairs. The OUTER ship could be torpedoed by an approach over the water. What about the inner ships - masked by Ford Island and the ship beside them?
The idea was to do nasty damage to them too - and that is why the development of this bombing technique. But it needed more than a weapon - they had to get accurate enough to insure hits. Fujida - bomber commander - set out to do that - and did it - in practice at Kagoshima. He changed the vic from 3 to 5. He did a number of other things - and in the end it was concluded the whole fleet could be targeted. Since every BB was indeed seriously damaged - the concept clearly worked.

[el cid again]

No one has presented the slightest rationale for a 22,500 per cent variation in bomb accuracy - which is the values found in CHS and RHS - and these may well be inherited from stock.

No one has presented the slightest rationale to believe a dumb bomb is more accurate because it is heavier. IF they had, I am certain it would not be measured in tens of thousands of per cent better.

Clearly we need a reform.

Clearly we should not risk using a value so low it does not work - and WITP does have minimum accuracy values for some things.

I will adopt the smallest value known to work on a uniform basis unless there is a reason to change it.

For Cluster bombs, there is a reason - so we assume you have three bombs inbound - each equally dumb - each with its own chance of a hit on this die roll - because all were release together.

For the 800 kg bombs - mainly because of the few units using it and because of the great skill and practice of those units - we will skew it slightly - using the historical data rather than a guess. We will use accuracy = 7 instead of 4. This is a vast decrease from the value used now (75). But I fear complaints it is too hard to score hits in the face of AA - and they WERE that accurate - so we have a cause to so rate them.

I cannot work with the Command at Sea "Axis" modifier - because our bombs are used by both sides. Also WITP does have national modifiers. We can hope these are right (somehow I doubt the Axis were given a bomb advantage but we can hope) and if not, Matrix can fix it bye and bye if it wants to. But we cannot do it in the data here - our bombs are used by both sides. In AE we can look at this again - if data suggests there is no such advantage we can use Axis only bomb devices.

[Shark7]

Ah, I see, you went by the paper rules, where I was basing off of HCE. It's not really different except in the way implemented. Just all the info you have in tables is just embedded into the DB entries in HCE.

As far as a fix for WITP, unless you did multiple entries for each weapon with an accuracy based to work with the bombing types, I can't really see being able to model the accuracy for each situation 100% accurately. Because as you pointed out, even variations in altitude will affect accuracy. There may be a way I don't know of though.

[el cid again]

It isn't our task here to worry about altitude, target type, target speed, or even bomber type:

WITP CODE will do this for us (well or poorly we cannot know - but it cannot do well unless the bombs are defined to a uniform standard - it can be fixed if need be by Matrix).

It is OUR task to get the devices right. We need to define a standard accuracy for a dumb bomb. Whatever we decided - it should not let one be 22.5 times more accurate than another - unless for some reason is really was better. The CODE will take the base devices and modify the chances in any given mission - say for altitude of release - or if on a dive bomber - or if the target is moving - etc.

[el cid again]

It ONLY adds device files.

These ONLY change bomb devices.

The changes are to adopt a uniform accuracy rating for single dumb bombs (cluster bombs are not changed and remain based on the sum of three dumb bombs) with a single exception - the 800 kg AP bomb - used only rarely (and under code control in strictly historical scenarios) - by one side - by units which achieved a known accuracy. The base accuracy used here is 4 and the 800 kg accuracy used is 7 while the cluster accuracy used is 12.

One other change is that the dual purpose 60 kg bomb or DC is re rated as a ASW device. I think this will work as a bomb just as well as ever - I am not sure if any ASW device works from planes? - but IF they do - they surely need to be defined as such and given a depth rating. I assigned depth = 150 because this device is used mainly for subs seen from aircraft (substantially Japanese flying boats and Ansons).

This update should be installed on top of comprehensive update 7.94 and it can be laid over micro update 7.941.

Test series 11 will use these files.

If you are contrarian and LIKE bomb devices with a 22,500 per cent variation in accuracy - simply do not install this microupdate - and you will retain the old system.

[el cid again]

RHSCVO 7.942 without modification - no optimization of attack altitude: land attacks

Day Air attack on Singapore [UK] , at 22,51

Japanese aircraft
G3M2 Nell x 80
G4M1 Betty x 27

Allied aircraft
Buffalo/F2A x 11

Japanese aircraft losses
G3M2 Nell: 11 damaged
G4M1 Betty: 4 destroyed, 4 damaged

Allied aircraft losses
Buffalo/F2A: 4 destroyed, 4 damaged
Vildebeest/Vincent: 1 destroyed
Swordfish I: 1 destroyed
Do 24K-2: 1 destroyed

Airbase hits 1
Runway hits 10

Aircraft Attacking:
12 x G3M2 Nell bombing at 15000 feet
12 x G3M2 Nell bombing at 15000 feet
20 x G4M1 Betty bombing at 15000 feet
20 x G3M2 Nell bombing at 15000 feet
15 x G3M2 Nell bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
4 x G3M2 Nell bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
5 x G3M2 Nell bombing at 15000 feet
7 x G3M2 Nell bombing at 15000 feet
2 x G3M2 Nell bombing at 15000 feet
--------------------------------------------------------------------------------
Day Air attack on Angeles/Clark [PH] , at 43,51

Japanese aircraft
A6M2 Zeke x 115
G3M2 Nell x 43
G4M1 Betty x 53

Allied aircraft
P-26A Peashooter x 4
P-35A Hawk x 6
P-40B Tomahawk x 3
P-40E Warhawk x 4

Japanese aircraft losses
A6M2 Zeke: 1 destroyed
G4M1 Betty: 1 damaged

Allied aircraft losses
P-26A Peashooter: 10 destroyed
P-35A Hawk: 8 destroyed
P-40B Tomahawk: 11 destroyed
P-40E Warhawk: 11 destroyed
B-17D Fortress: 5 destroyed


Allied ground losses:
28 casualties reported
Guns lost 2
Vehicles lost 1

Airbase hits 25
Airbase supply hits 7
Runway hits 149

Aircraft Attacking:
9 x G3M2 Nell bombing at 15000 feet
6 x G3M2 Nell bombing at 15000 feet
6 x G4M1 Betty bombing at 15000 feet
6 x G4M1 Betty bombing at 15000 feet
7 x G3M2 Nell bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
4 x G4M1 Betty bombing at 15000 feet
6 x G4M1 Betty bombing at 15000 feet
6 x G4M1 Betty bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
4 x G4M1 Betty bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
3 x G3M2 Nell bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
3 x G4M1 Betty bombing at 15000 feet
--------------------------------------------------------------------------------
Day Air attack on Angeles/Clark [PH] , at 43,51

Japanese aircraft
G4M1 Betty x 15
Ki-46-II Dinah x 1

Allied aircraft
no flights

Japanese aircraft losses
G4M1 Betty: 1 damaged

Allied aircraft losses
P-40B Tomahawk: 2 destroyed
B-17D Fortress: 1 destroyed

Airbase hits 2
Airbase supply hits 2
Runway hits 24

Aircraft Attacking:
8 x G4M1 Betty bombing at 15000 feet
7 x G4M1 Betty bombing at 15000 feet
--------------------------------------------------------------------------------

[el cid again]

Same - naval attacks:

Day Air attack on Cebu [Cebu] , at 43,57

Japanese aircraft
A5M4 Claude x 16
B5M/B5N Kate x 18

No Japanese losses

Allied Ships
AK Governor Smith, Bomb hits 2, on fire, heavy damage

Aircraft Attacking:
18 x B5M/B5N Kate bombing at 5000 feet
--------------------------------------------------------------------------------
Day Air attack on Pearl Harbor [Oahu] , at 114,72

Japanese aircraft
A6M2 Zeke x 45
D3A2 Val x 126
B5M/B5N Kate x 144

Allied aircraft
P-40B Tomahawk x 1

Japanese aircraft losses
A6M2 Zeke: 4 destroyed
D3A2 Val: 14 destroyed, 16 damaged
B5M/B5N Kate: 6 destroyed, 10 damaged

Allied aircraft losses
P-40B Tomahawk: 37 destroyed
PBY-5 Catalina: 26 destroyed
B-18A/B-23/F-2 Bolo: 13 destroyed
P-36A Mohawk: 16 destroyed
C-47/R4D-5 Skytrain: 2 destroyed
SBD-3/4 Dauntless: 7 destroyed
F4F-3 Wildcat: 7 destroyed
A-20B Boston: 7 destroyed
OS2U-3 Kingfisher: 3 destroyed
B-17D Fortress: 3 destroyed
B-17E/F Fortress: 2 destroyed
C-32/36/39/40+BT-32: 5 destroyed

Allied Ships
BB Tennessee, Bomb hits 8, on fire, heavy damage
BB California, Bomb hits 5, Torpedo hits 2, on fire, heavy damage
BB Nevada, Bomb hits 12, Torpedo hits 2, on fire
BB Oklahoma, Bomb hits 10, Torpedo hits 1, on fire
AK Mercury, Bomb hits 1, on fire
BB Maryland, Bomb hits 7, Torpedo hits 3, on fire, heavy damage
BB West Virginia, Bomb hits 6, Torpedo hits 4, on fire, heavy damage
AO Ramapo, Torpedo hits 1
BB Pennsylvania, Bomb hits 5, Torpedo hits 2, on fire, heavy damage
CL Raleigh, Bomb hits 2, Torpedo hits 1, on fire
BB Arizona, Bomb hits 5, Torpedo hits 1, on fire, heavy damage
CA San Francisco, Bomb hits 1
CL Detroit, Bomb hits 1, Torpedo hits 1, on fire
SS Cachalot, Bomb hits 1, on fire
CL St. Louis, Bomb hits 1, on fire
CA New Orleans, Bomb hits 1
CL Helena, Bomb hits 1


Allied ground losses:
1 casualties reported
Guns lost 1

Airbase hits 31
Runway hits 125

Aircraft Attacking:
10 x A6M2 Zeke attacking at 100 feet
14 x D3A2 Val bombing at 2000 feet
24 x B5M/B5N Kate launching torpedoes at 200 feet
12 x A6M2 Zeke attacking at 100 feet
24 x D3A2 Val bombing at 2000 feet
27 x B5M/B5N Kate bombing at 9000 feet
14 x D3A2 Val bombing at 2000 feet
17 x B5M/B5N Kate launching torpedoes at 200 feet
15 x D3A2 Val bombing at 2000 feet
16 x B5M/B5N Kate bombing at 9000 feet
23 x D3A2 Val bombing at 2000 feet
27 x B5M/B5N Kate bombing at 9000 feet
22 x D3A2 Val bombing at 2000 feet
27 x B5M/B5N Kate bombing at 9000 feet

Day Air attack on TF, near Kota Bharu [Malaya] at 24,45


Allied aircraft
Blenheim IV/Bolngbrk x 11
Vildebeest/Vincent x 16


Allied aircraft losses
Vildebeest/Vincent: 2 destroyed, 2 damaged

Japanese Ships
BB Kongo
BB Haruna, Bomb hits 1

Aircraft Attacking:
8 x Blenheim IV/Bolngbrk bombing at 15000 feet
3 x Vildebeest/Vincent bombing at 5000 feet
3 x Blenheim IV/Bolngbrk bombing at 15000 feet
1 x Vildebeest/Vincent bombing at 5000 feet
2 x Vildebeest/Vincent bombing at 5000 feet
4 x Vildebeest/Vincent bombing at 5000 feet
4 x Vildebeest/Vincent bombing at 5000 feet

[el cid again]

Conclusion: bomb hit rates are not vastly changed.

The relative chance of a hit beween bomb types should be substantially equalized.

[herwin]

ORIGINAL: spence

Presumably your figures pertain to horizontal bombing of stationary targets only.

According to Shattered Sword Akagi was attacked by 3 SBDs at Midway (divebombing) which scored 1 hit and 1 near miss. Not sure how one might record a near miss a la WitP (which may well have caused damage resulting in Akagi's rudder subsequently becoming jammed) but in any case the single solid hit by itself would record a hit percentage of 33 percent.

May we all assume that the incredible accuracy reported by Fujita is, conveniently, almost alone a "survivor" amongst all those Japanese records destroyed at the end of the war?

Phit for dive bombing by experienced pilots against maneuvering ships in WWII was about 22% per aircraft.

[Bogo Mil]

I think larger bombs should be a bit more accurate, at least from medium to high altitude:
1. They fall down faster, thus it's easier to evaluate the lead and the target has less time to evade.
2. They are less susceptible to crosswinds.

I don't say it should be 22,500%, but some difference is reasonable, imho.

Edit: There is a third reason for a higher accuracy of the big bombs: In WITP, everything that does damage is a "hit". A small bomb has to hit the target directly to cause damage, a large bomb can cause major damage by near misses. Thus you have a significantly larger "hit area" if you attack with large bombs.