Allied submarine torps vs. DDs.

[JocMeister]

Lately I have noticed something very odd in my PBEM vs obvert. My subs have played a cat and mouse game with his DDs all over the map. It should have worked out very well except for the fact that ALL hits have been "duds".

I don´t have the exact number but I think I´m approaching 20-25 hits during the last month and against his DDs I have a 100% dud rate. Not a single one have exploded. Against other shipping it works normally.

I´m thinking something is not right here. Either they actually are duds in which case this perhaps could be some bug. Or its simply a display error and the duds are actually misses. In that case I guess its a bug as well!? But I do get misses pretty often too.

Very weird! [&:]

[Puhis]

Bad luck, nothing more. Allied subs have sunk enough of my DDs.

[JocMeister]

Whats the probability for getting 20-25 duds in a row on DDs only but getting normal hits on all other targets? I think something is amiss...

[witpqs]

ORIGINAL: JocMeister

Whats the probability for getting 20-25 duds in a row on DDs only but getting normal hits on all other targets? I think something is amiss...

IIRC the dud rate on those USN Mk14 torps is 80% until it begins getting adjusted downward. To get 20 duds in a row you basically get .80**20, which is 0.1153.

In other words a 1.15% chance for them all in a row to be duds. Said another way, for every group of 20 Mk14 hits, 1 out of 86.7 times all 20 of the hits will be duds.

So it's rare but frequent enough that people on this forum will experience it, and someone will notice it and post about it.

Feel better? [8D]

[JocMeister]

Slightly [;)]

I´m far from convinced though! [:'(]

[michaelm75au]

Open up the editor for the scenario you are playing, have a look at the dud rate for the torpedo the subs are using in the Device tab?
What is it? Or just paste the picture of the torpedo device screen.

[edit]
In scenario #1, 21 in Mk14 torpedo has a dud rate of 80.
From about Jan 43, the rate drops to by 20 (to 60) and 8 months later to 10.

[JocMeister]

michelm,

Yes I´m playing scenario 1. I just find it very odd to have a 100% dud rate against DDs only. Against other shipping I do get the occational dud. But I might just be a crazy fluke. Will count more thoroughly from now and see what happens!

[obvert]

I just noticed this here. Jocke has a point here, because the number of duds on DDs is staggeringly larger than the dud rate on any other ship. It is now March 43 so the torps should be hitting the majority of the time at least. For the past three months the hits have increased on every other kind of ship.

My feeling is that the number of hits is about right, but the note is wrong, listing duds when they should be misses. I rarely hit Allied subs either, especially those involved in ASW, but all of those non-hits are listed as misses. So it's probably semantics, but hard to handle when it keeps saying they are duds. It is on average one per turn.

[LoBaron]

C'mon guys, think twice about this issue. Your average DD is brutally hard to hit by a torp.

Just weeks ago there was exactly the same suspicion against torps hitting CVs. I will simply post the link, since it does not make sense
to type everything again, but if you are interested what is the most probable cause for what you see, read my post #28. You have to
shift numbers and percentages, but the result is pretty much the same.

Seriousely now.....

I have sunk DDs by MK14s, and I have sunk DDs by MK10s, not many, but I don´t expect that. 95% of my torps fired against a DD hull are a miss,
and I am absolutely not surprized, this should be the case.

obvert, before I forget: your MK14 dud rate in March '43 is 60%, so duds are still the majority IF you hit at all. Hit percentage and dud percentage are two different things, if
you think the hit rate (as opposed to a torp miss) should increase later war you are mixing up things. It doesn´t.


I give this 'issue' a 99.99% chance to turn out to be an occurance within normal statistical distribution.

[PaxMondo]

Not to mention FOW is present here as well ....
 
 

[LoBaron]

FOW is a factor as well, and also I forgot to quote the most valuable post in the thread linked above:

ORIGINAL: Don Bowen

There are a number of issues in this thread, and perhaps a little confusion about how some things work.

A sub torpedo attack involves:[ol]
[*] Can the sub fire a torpedo (or more than one)?

• Is the target worth a torpedo (with fog of war)?
• Can the sub get into firing position?
  • Relative speed of sub and target TF
  • Detection level of sub and TF
  • Number and skill of escorts
  • Skill and aggression of sub commander

[*] Does the torpedo hit the target?

• Accuracy of torpedo (from device table)
• Speed and maneuverablilty of target

[*] Does it explode?

• Dud rate of torpedo (from device table)
• Nothing else

[/ol]

To all of these, add a little luck. Or rather, random chance. For just about everything in AE, there is a random chance. A torpedo with an 80% dud rate would have an 80% chance of failure for each hit. No long term averaging or any such thing. Just a random 80%. That could mean 10 explosions in a row or 500 duds in a row. It's just random.

See the part bolded by me: You got about the worst possible combination against you to enable a torp hit when you fire on a DD.

Also, you can see by Don´s post that there is absolutely no relation to ship class in the hit calculations, with the possible exception of the decision to fire on target in the first place.

[JocMeister]

Please reread my first post. The question was never about the amount of misses or hits for that matter. The hit or miss percentages are irrelevant in this case. The question was about the very odd occurrences of "duds" ONLY against DDs.

If I was unclear in my first post I apologize.

A "dud" means a "hit without explosion". Since my report concerns "duds" the possibilities of hitting a DD is totally irrelevant in this case (but it should be noted that the US subs through a period of the war targeted Japanese DDs with great success).

The issue if I could call it that is the weird number of "duds" IE hits that fail to explode. I´m not very good at math but if there is a 40% risk of a dud and it happens 27 times in a row ONLY on DDs the statistical probabilities should be pretty low. Perhaps witpqs can do the math again? [:D]

Hence I made the post.

There is also the question whether or not the reported "duds" we see in the replay actually are duds.

[LoBaron]

ORIGINAL: JocMeister

Please reread my first post. The question was never about the amount of misses or hits for that matter. The hit or miss percentages are irrelevant in this case. The question was about the very odd occurrences of "duds" ONLY against DDs.

If I was unclear in my first post I apologize.

A "dud" means a "hit without explosion". Since my report concerns "duds" the possibilities of hitting a DD is totally irrelevant in this case (but it should be noted that the US subs through a period of the war targeted Japanese subs with great success).

The issue if I could call it that is the weird number of "duds" IE hits that fail to explode. I´m not very good at math but if there is a 40% risk of a dud and it happens 27 times in a row ONLY on DDs the statistical probabilities should be pretty low. Perhaps witpqs can do the math again? [:D]

Hence I made the post.

There is also the question whether or not the reported "duds" we see in the replay actually are duds.

JocMeister, I did not misread your first post.

The reason for me pointing out differences between miss and dud was that these topics usually generate a lot of "yeah, this happens to me as well,
this must be an issue" follow-ups which often do not discern as you did, and in many cases are completely unrelated to your specific experience. This
generates an ammount of false evidence that only looks convincing because the other 99% of players not experiencing the same issue don´t bother to
post "but my DDs get sunk as any other ship". [;)]

The chance for a high number of duds in a row is real, there are thousands of PBEMs being played, so the chances of some statistical result occuring
with a 1% probability is extremely high.

As Don said, dud rate has nothing to do with the target type, the only calculation made is based on the torps´ dud rate.

FOW might play a role as well, mabe masking some misses as duds or vice versa, but even if this turns out wrong there is too much fact opposing the assumption that an issue exists.

For this to be the case there must be a major fubar concerning torp explosion calculations, somehow factoring in ship types, which nobody noticed over
3 years, not even modders like the DaBabes team. And it would oppose my personal experience that I did not notice any difference in dud probability
on DDs compared to other ship types.

Now, IMHO this is enough to estimate the chances of a statistical extreme happening in one of a couple of thousands of games (yours) much higher
than the chances that a bug exists which for some reason favors a DD´s survivability when hit by a torp over that of any other ship type.

[KenchiSulla]

An undamaged DD is very hard to hit. Your succes rate against damaged naval vessels (DDs, CLs etc) should be a lot higher.

Speed is a factor, and the manoeuver rating of the ship. The higher these ratings, the harder a target is to hit..

[PaxMondo]

ORIGINAL: JocMeister

There is also the question whether or not the reported "duds" we see in the replay actually are duds.

Pretty sure that FOW is involved in this. It would track reality if it did.

[JocMeister]

Whatever it is you can now add 2 more! Closing on about 30! [:D]

[Cavalry Corp]

I notice against all allied DD it says miss and against Jap DD it says dud, I think the message dud should mostly say miss?

[JocMeister]

ORIGINAL: cavalry

I notice against all allied DD it says miss and against Jap DD it says dud, I think the message dud should mostly say miss?

Thats what I´m starting to suspect as well!

[obvert]

ORIGINAL: LoBaron

C'mon guys, think twice about this issue. Your average DD is brutally hard to hit by a torp.

Just weeks ago there was exactly the same suspicion against torps hitting CVs. I will simply post the link, since it does not make sense
to type everything again, but if you are interested what is the most probable cause for what you see, read my post #28. You have to
shift numbers and percentages, but the result is pretty much the same.

Seriousely now.....

I have sunk DDs by MK14s, and I have sunk DDs by MK10s, not many, but I don´t expect that. 95% of my torps fired against a DD hull are a miss,
and I am absolutely not surprized, this should be the case.

obvert, before I forget: your MK14 dud rate in March '43 is 60%, so duds are still the majority IF you hit at all. Hit percentage and dud percentage are two different things, if
you think the hit rate (as opposed to a torp miss) should increase later war you are mixing up things. It doesn´t.


I give this 'issue' a 99.99% chance to turn out to be an occurance within normal statistical distribution.

Everything you are saying is supported by what we are saying. [:)] We both realize that hits against DDs are rare. I feel fine sending out my best DDs on ASW (I'm playing the Japanese side by the way, so they're not my Mk 14s).

We're simply noticing a difference between the messages that are put in reports between the Allied side and the Japanese side. The Allied 'misses' are most often called duds. The 'misses' by IJN subs are called misses. They are very rarely called duds. It's that simple. But that difference could be confusing, especially for a new player, and lead them to make decisions based on that information.

[chuckj118]

There is an issue with torpedoes not exploding when fired at IJN DD's. I am currently up to 4/20/44 in a boosted Japanese game and so far I have sunk EXACTLY 3 DD's with submarine fired torpedoes. One Mk 14 and 2 Mk 10's. Five have been sunk by air dropped torpedoes. At least 15 additional IJN DD's have been struck by subs but have come up with the dud response. IJN E boats and SC's do not seem to be included in this ... they have been struck many times.

Historically about 40 IJN DD's were sunk by American Subs. I am WAY below that number. If current averages persist I will sink an additional 3 IJN DD's before the end of the war.

If this hasn't been looked at it needs to be.