"The All Knowing" destroyer syndrome

[AndrejD]

Originally Posted by kapitan_zur_see

Just attacked a convoy and started to get hunted by two destroyer. they would ping relentlessly, as expected but man...!

No matter what I would do, they would always track me faultlessly downright to a precision my top of the line car GPS couldn't even reach! no matter what evasive maneuver I would try during a depthcharge run, the destroyer would follow my exact turn even double turns, being at silent running or full speed. Sure they would miss a lot of Depthcharges but...

!!! Inbetween those, no matter how hard I would try to change course, change depth, sticking to the bottom or sticking to near periscope depth to avoid asdic detection cone, running at silent or mid speed, they would always track me with the precision of a GPS.

Damn! even when they ran out of depthcharges, they wouldn't even abandonned but would relentlessly do circles around me for a whole day!!! eventually forcing me to surface where I got killed.

How do you guys do to evade from such all knowing über creatures?!?
Are there some techniques I somehow didn't figured out??

That AI is so messed up
On second hand, maybe it's that ducimus destroyer AI tweaking, I remember having the same syndrome with trigger maru overhauled...

U use somekind of a mod ?
I can`t get the DD`s to attack me...

My Patrol report:
http://www.subsim.com/radioroom/showthread.php?t=164347

[sergei]

Originally Posted by AndrejD

U use somekind of a mod ?
I can`t get the DD`s to attack me...

Try this
http://www.subsim.com/radioroom/showthread.php?t=163905
With it I think you'll find the problem is getting away from the destroyers!

[utops]

Originally Posted by skwasjer

I sank a carrier by sneaking inside the protective ring of 10 DD's (I was like wtf?), this was a night attack, submerged, engines off. I fired a salvo of 4 from about 600m away. When they hit, the 5 DD's that were behind me starting using their searchlights to the outside of the ring and searched there, and obviously they never found me as I was on the inside (I snuck out of the gap they left on the rear). So apparantly they 'can' be confused about where the exact location of the attack came from...

In game loading screen, there is a tip related to such a behaviour, it say that, the best method of atacking well protected convoys is to get inside because escorts will be always looking for you outside.

[thruster]

without trying to hijack the thread,
can someone confirm that damaged ships eventually slow and drop out of the convoy screen?

cheers

[Merlin.75]

Originally Posted by thruster

without trying to hijack the thread,
can someone confirm that damaged ships eventually slow and drop out of the convoy screen?

cheers

I can confirm they have done this.

[Furia]

Originally Posted by kapitan_zur_see

Just attacked a convoy and started to get hunted by two destroyer. they would ping relentlessly, as expected but man...!

No matter what I would do, they would always track me faultlessly downright to a precision my top of the line car GPS couldn't even reach! no matter what evasive maneuver I would try during a depthcharge run, the destroyer would follow my exact turn even double turns, being at silent running or full speed. Sure they would miss a lot of Depthcharges but...

!!! Inbetween those, no matter how hard I would try to change course, change depth, sticking to the bottom or sticking to near periscope depth to avoid asdic detection cone, running at silent or mid speed, they would always track me with the precision of a GPS.

Damn! even when they ran out of depthcharges, they wouldn't even abandonned but would relentlessly do circles around me for a whole day!!! eventually forcing me to surface where I got killed.

How do you guys do to evade from such all knowing über creatures?!?
Are there some techniques I somehow didn't figured out??

That AI is so messed up
On second hand, maybe it's that ducimus destroyer AI tweaking, I remember having the same syndrome with trigger maru overhauled...

Hehe nothing different than you would experience if we would have a human controlled DD like in the old times of SH II and DC

If the acoustic conditions are good, you can not simply escape 2 alerted DD once they locate you.

Maybe you guys are getting too used to facing AI DD with their poor perfomance and lack of consistence in tactics. Either they are dumb or they are Terminators.

I can't wait to have a human controlled DD for SHV

And remember Surface Escorts rule the seas

[Mondaiji]

Originally Posted by thruster

without trying to hijack the thread,
can someone confirm that damaged ships eventually slow and drop out of the convoy screen?

cheers

That depends on the convoy. For example i had a convoy of something around 9 destroyer 1 battle cruiser 1 battleship and a aircraft carrier. If i disable the aircraft carrier the convoy stay with the battleship .. well 2 destroyer stay with the carrier the rest keeps going. If i disable the battleship 7 destroyer stay with it. So i would say some ships have a escort that always stay's with them.

[Kretschmer the IV]

I experienced a nice addition to the AI (stock).

Beeing hunted for almost 24 hours, 2 of 3 destroyers went to the convoy. I was going to periscope depth, and took a look.. There he was, the 3rd destroyer about 300m of my position with shutted down engine lol.

He saw my periscope, attacked. The 2 destroyers who left, came back after 4 hours ingame. Trying to escape on 1 knots, i activated tc. did not saw that the depth is increasing (bug ) and i went too far.. BTW any way to fix this "sub is not holding ordered depth when passing over 120m?"

[Bilge_Rat]

couple of points:

1. history: I am in the process of re-reading Blair vol. 1, and there are many examples of subs being held down or attacked by HK groups in the early years.

Johnnie walker's escort group was protecting Gibraltar convoys and accounted for many U-boat kills. They would gang up 3-4 escorts on one contact and just keep hammering until they were certain of a kill. They killed the U-boat Ace Engelbert Endrass that way in december 41.

There are also stories of U-boats being held down for a long time. The U-89 was held down for 31 hours in summer 42, until it managed to escape.

2. the game: you have to remember that the AI has 2 states, he has not detected and ignores you or you are detected, in which case you will be attacked until the escort loses contact for a fixed period of time (default is 15 minutes), after which he will go back on course.

I am not the expert, but there are many factors that will determine if you are detected underwater: skill of the escort (there are 5 from green to elite), your speed, your depth, thermal layer, speed of the escort, sea state. There is also 2 doctrines: aggressive/defensive, although I am not sure what they do, and various AI scripts. If a ship is torpedoed or you are detected by a ship or escort, other escorts near by will come over to hunt you down.

you can see an example of how the AI works here:

http://www.subsim.com/radioroom/showthread.php?t=163304


for the moment, I am sticking with the stock AI, until I can figure out how it works. As Ducimus as already shown, it is very easy to create an AI that will find you and kill you every single time if that is what you wish.

[longam]

Originally Posted by utops

In game loading screen, there is a tip related to such a behaviour, it say that, the best method of atacking well protected convoys is to get inside because escorts will be always looking for you outside.

Wasnt that the way they did it early on? Also the date would make a difference on how good the sonar was at the time I would think.

[senjorlossi]

Back to the main topic:


I can confirm that in my (in this direction) unmodded game the destroyers exactly konw ANY move I make (OK, as long as they have contact with me). That has really annoyed me already in SH 3, and now it´s back aganin:

Via outide cam I could see that approaching Destroyers (running high speed on a DC run) would always react to any evasive action I would take, even when it is already almost directly above me. For me, this really messes the gameplay, since I have no chance of doing some sort of "last second" maneuvers. The destroyer will always run directly over my position and drop depth charges there. So evasing is always simply a matter of depth and speed, to move out before the DCs explode.

As far as I know, a real destroyer running in at high speed would, at some point, loose contact due to speed and noise and drop the DCs blind at the spot where the U-boat would be assumed to be. Maybe the Destroyer-Commander would take in count a possible evasive maneuver of the U-boat and drop the DCs somewhat to the left or right. But not always right on top of the boat.

I think there should be some "blindness" added to the destroyers when running flank speed on an attack run.

[U-Bones]

Originally Posted by Bilge_Rat

couple of points:

1. history: I am in the process of re-reading Blair vol. 1, and there are many examples of subs being held down or attacked by HK groups in the early years.

Johnnie walker's escort group was protecting Gibraltar convoys and accounted for many U-boat kills. They would gang up 3-4 escorts on one contact and just keep hammering until they were certain of a kill. They killed the U-boat Ace Engelbert Endrass that way in december 41.

There are also stories of U-boats being held down for a long time. The U-89 was held down for 31 hours in summer 42, until it managed to escape.

2. the game: you have to remember that the AI has 2 states, he has not detected and ignores you or you are detected, in which case you will be attacked until the escort loses contact for a fixed period of time (default is 15 minutes), after which he will go back on course.

I am not the expert, but there are many factors that will determine if you are detected underwater: skill of the escort (there are 5 from green to elite), your speed, your depth, thermal layer, speed of the escort, sea state. There is also 2 doctrines: aggressive/defensive, although I am not sure what they do, and various AI scripts. If a ship is torpedoed or you are detected by a ship or escort, other escorts near by will come over to hunt you down.

you can see an example of how the AI works here:

http://www.subsim.com/radioroom/showthread.php?t=163304


for the moment, I am sticking with the stock AI, until I can figure out how it works. As Ducimus as already shown, it is very easy to create an AI that will find you and kill you every single time if that is what you wish.

Given what we have on hand, I am thinking better behavior may be achieved with a combo of the AI mod combined with a shorter than 15 minute "last contact timer". 15 minutes is an eternity vs more than one DD, they can easily cover a lot of area to reaqquire, while also having one sit still and listen forcing you to be very slow. If DC's were more accurate or damaging, it would almost always be short and not so sweet.

The problem would be finding the sweet spot between giving you a chance vs multiples and being able to easily escape a single DD. Perhaps givening the DDs a smaller prosecution window can be balanced by giving them a better chance to exploit the contact - harder hitting DC's ? But first we need to see aggressive behavior that still allows a REAL chance to escape.

With the current AI mod, the behavior of the DD's is good, as well as the sensor capabilities, but... maybe too good still. It ends up with DDs that are aware but somewhat impotent, as likely to kill you by denying the surface as by DC, as opposed to less certain but much more dangerous.

IMO a happy medium on the AI/sensors would be a better starting point than either stock or the current AI mod. Making them give up in 5 minutes ( or 15 for that matter ) just seems like the wrong way to prevent reacquiring. It should be because they "guess" incorrectly and look in the wrong place long enough for you to get away, ie REALLY part of the AI as opposed to just being more aware.

[Bilge_Rat]

Originally Posted by U-Bones

IMO a happy medium on the AI/sensors would be a better starting point than either stock or the current AI mod. Making them give up in 5 minutes ( or 15 for that matter ) just seems like the wrong way to prevent reacquiring. It should be because they "guess" incorrectly and look in the wrong place long enough for you to get away, ie REALLY part of the AI as opposed to just being more aware.

It will require testing. My thinking is more along the line of increasing slightly the passive sensors of the AI, increasing more strongly the active sonar and increasing the time before contact lost until 30 mins.

This way the ability of an escort to just hear your boat before or after an attack is not omniscient, but if they find you, they will look for you for a longer time and be able to hold contact better with active sonar.

from my point of view, the big problem is trying to figure out how far and deep the passive sonar of escorts should extend. Now that we can "see" the escorts sonar, it is easier to figure out how it works and the impact tweaking can have. For example, this was from Ducimus's first WIP AI mod:




my boat is silent running at depth of 120 meters (390 feet) and the passive sonar of a veteran skill 1942 escort still extends out to 800 meters. It does not take much tweaking of the sonar ability or thermal leyer to create results which are out of whack. (note this is only for illustration purposes:this has now been cut back in the latest mod).

the problem is finding the happy medium so that it is not too easy or too hard, while maintaining the illusion of "realism" within the constraints of the game system.

[Ducimus]

the problem is finding the happy medium so that it is not too easy or too hard, while maintaining the illusion of "realism" within the constraints of the game system.

Yup. I wasn't done yet, but posted what i had cause i was PO'ed at DRM.

If you wanted to make the AI tweaks i posted easier......

The noise factor for hydrophones could probably be relaxed a bit more. To the tune of adding 0.05 to 0.1 to the current hydrophone noise factor. (0.45 i think it currently is)

Surface factor on active sonar could maybe be increased another by 40 or 50. Just an off the top of my head guess.

Thermal layers, id leave right out. This isn't the pacific. In the atlantic, thermal layers were too deep to reach.