Aurora 4x

C# Aurora => General Discussion => Topic started by: Zeebie on October 22, 2020, 08:01:39 AM

Title: Anti-missile hit probability
Post by: Zeebie on October 22, 2020, 08:01:39 AM
So this keeps happening:

(https://i.imgur.com/OEj5pdt.jpg)

The stated hit chance is ~20%, but I will launch hundreds of missiles and not score a single hit.  Am I not understanding something about what "Chance to Hit" means?
Title: Re: Anti-missile hit probability
Post by: Jorgen_CAB on October 22, 2020, 09:42:20 AM
Can you paste the design of those AMM, do you have at least 1 point of damage on their yield on them?
Title: Re: Anti-missile hit probability
Post by: Zeebie on October 22, 2020, 10:11:58 AM
Sure, here it is. It has a size 1 warhead.

Vaccine III AMM (1490)    Speed: 38,400 km/s    End: 0.3m     Range: 0.7m km    WH: 1    Size: 1    TH: 473/284/142
Title: Re: Anti-missile hit probability
Post by: Kylemmie on October 22, 2020, 10:50:10 AM
side note - Vaccine AAM. . . . . . thanks for the chuckle!
Title: Re: Anti-missile hit probability
Post by: Garfunkel on October 22, 2020, 11:27:44 AM
Can you show us the full combat log? There should be a break down of things affecting ToHitChance
Title: Re: Anti-missile hit probability
Post by: Zeebie on October 22, 2020, 11:50:59 AM
Can you show us the full combat log? There should be a break down of things affecting ToHitChance

How do I access the full combat log?  This is all I get in the events window.
Title: Re: Anti-missile hit probability
Post by: Iceranger on October 22, 2020, 01:39:20 PM
Can you show us the full combat log? There should be a break down of things affecting ToHitChance
Sadly, the breakdown is no longer available in C#
Title: Re: Anti-missile hit probability
Post by: Iceranger on October 22, 2020, 01:49:45 PM
So this keeps happening:

(https://i.imgur.com/OEj5pdt.jpg)

The stated hit chance is ~20%, but I will launch hundreds of missiles and not score a single hit.  Am I not understanding something about what "Chance to Hit" means?
How fast are the incoming missiles?
Title: Re: Anti-missile hit probability
Post by: Zeebie on October 22, 2020, 02:49:41 PM

How fast are the incoming missiles?

60k. But shouldn't that be included in the calculation of chance to hit?
Title: Re: Anti-missile hit probability
Post by: TheTalkingMeowth on October 22, 2020, 03:30:49 PM
Hmmm. With the attack missiles being faster than the interceptors, you have a serious problem; due to the way aurora handles increments, they may never intercept and get to make an attack roll.

But from what you posted, they ARE getting to make an attack roll. It's just missing.
Title: Re: Anti-missile hit probability
Post by: Iceranger on October 22, 2020, 03:48:46 PM

How fast are the incoming missiles?

60k. But shouldn't that be included in the calculation of chance to hit?

It should be, speed, agility, and ECM/ECCM should all be included in the displayed hit chance, based on tests in 1.11. That's why I was asking for the speed of the missiles so I can hopefully narrow down what went wrong.

Based on your AMM's specs, and displayed lowest hit chance, the enemy missile should be around 67600km/s. Is that the case? Do you notice any mentioning of ECM levels on the incoming missiles?
Title: Re: Anti-missile hit probability
Post by: Zeebie on October 22, 2020, 05:49:12 PM

It should be, speed, agility, and ECM/ECCM should all be included in the displayed hit chance, based on tests in 1.11. That's why I was asking for the speed of the missiles so I can hopefully narrow down what went wrong.

Based on your AMM's specs, and displayed lowest hit chance, the enemy missile should be around 67600km/s. Is that the case? Do you notice any mentioning of ECM levels on the incoming missiles?

Yes, that speed is correct. I don't remember seeing any ECM announcement.
Title: Re: Anti-missile hit probability
Post by: Iceranger on October 22, 2020, 06:42:03 PM
I don't seem to be able to reproduce the issue in my test setup.

AMM:
Code: [Select]
Missile Size: 1.0000 MSP  (2.50000 Tons)     Warhead: 1    Radiation Damage: 1    Manoeuvre Rating: 129
Speed: 20 000 km/s     Fuel: 150     Flight Time: 2 minutes     Range: 2.84m km
Cost Per Missile: 3.13932     Development Cost: 314
Chance to Hit: 1k km/s 2580%   3k km/s 860.0%   5k km/s 516%   10k km/s 258%

Target:
Code: [Select]
Missile Size: 3.00 MSP  (7.500 Tons)     Warhead: 0    Radiation Damage: 0    Manoeuvre Rating: 10
Speed: 40 000 km/s     Fuel: 1 675     Flight Time: 18 hours     Range: 2 556.3m km
ECM Modifier: 60%     ECCM Modifier: 60%
Cost Per Missile: 9.00     Development Cost: 900
Chance to Hit: 1k km/s 400%   3k km/s 133.3%   5k km/s 80%   10k km/s 40%

The hit chance would be
25800/40000 - 60% = 4.5%

Event log:
(https://cdn.discordapp.com/attachments/619231280713957406/768981322785226762/unknown.png)

So the displayed hit chance is correct (with rounding), and the AMMs actually hits something.

Of course, AMMs being slower than the target means there is a non-negligible chance of interception failure. But once the interception is successful, the hit rate seem to be expected.

I had multiple suspicions on why this could happen, but it seems the above disproves all of them:
Title: Re: Anti-missile hit probability
Post by: Jorgen_CAB on October 22, 2020, 07:02:45 PM
Could it just not be that the ASM have an ECM rating of 30 and therefore the chance of hitting become less then zero and that this simply is not displayed in the to hit chance even though it probably should?

At least this seem like the most likely explanation.

I think ECM should be emphasised in the to hit as it can be very decisive at times.
Title: Re: Anti-missile hit probability
Post by: Iceranger on October 22, 2020, 07:16:59 PM
Could it just not be that the ASM have an ECM rating of 30 and therefore the chance of hitting become less then zero and that this simply is not displayed in the to hit chance even though it probably should?

At least this seem like the most likely explanation.

I think ECM should be emphasised in the to hit as it can be very decisive at times.
In my example, the target missiles have ECM on them, and the displayed hit chance correctly considered it.
Title: Re: Anti-missile hit probability
Post by: Jorgen_CAB on October 23, 2020, 02:47:10 AM
Could it just not be that the ASM have an ECM rating of 30 and therefore the chance of hitting become less then zero and that this simply is not displayed in the to hit chance even though it probably should?

At least this seem like the most likely explanation.

I think ECM should be emphasised in the to hit as it can be very decisive at times.
In my example, the target missiles have ECM on them, and the displayed hit chance correctly considered it.

Ah... yes... I saw you wrote that after my post...

But could there be a problem with the log and what it show IF the ECM reduce the to hit below zero... perhaps should test that if that was not done?
Title: Re: Anti-missile hit probability
Post by: Iceranger on October 23, 2020, 09:20:32 AM
Could it just not be that the ASM have an ECM rating of 30 and therefore the chance of hitting become less then zero and that this simply is not displayed in the to hit chance even though it probably should?

At least this seem like the most likely explanation.

I think ECM should be emphasised in the to hit as it can be very decisive at times.
In my example, the target missiles have ECM on them, and the displayed hit chance correctly considered it.

Ah... yes... I saw you wrote that after my post...

But could there be a problem with the log and what it show IF the ECM reduce the to hit below zero... perhaps should test that if that was not done?

Unfortunately, that is not the case. If the expected hit chance is below 0, the AMMs won't auto fire at all.
(https://media.discordapp.net/attachments/619231280713957406/769203067500888124/unknown.png)

AMM:
Code: [Select]
Missile Size: 1.0000 MSP  (2.50000 Tons)     Warhead: 1    Radiation Damage: 1    Manoeuvre Rating: 100
Speed: 20 000 km/s     Fuel: 610     Flight Time: 10 minutes     Range: 11.55m km
Cost Per Missile: 2.5502     Development Cost: 255
Chance to Hit: 1k km/s 2000%   3k km/s 666.7%   5k km/s 400%   10k km/s 200%

Target:
Code: [Select]
Missile Size: 3.00 MSP  (7.500 Tons)     Warhead: 0    Radiation Damage: 0    Manoeuvre Rating: 10
Speed: 40 000 km/s     Fuel: 1 675     Flight Time: 18 hours     Range: 2 556.3m km
ECM Modifier: 60%     ECCM Modifier: 60%
Cost Per Missile: 9.00     Development Cost: 900
Chance to Hit: 1k km/s 400%   3k km/s 133.3%   5k km/s 80%   10k km/s 40%

Hit chance in theory:
20000/40000 - 60% = -10%

Title: Re: Anti-missile hit probability
Post by: Droll on October 23, 2020, 11:00:59 AM
Could it just not be that the ASM have an ECM rating of 30 and therefore the chance of hitting become less then zero and that this simply is not displayed in the to hit chance even though it probably should?

At least this seem like the most likely explanation.

I think ECM should be emphasised in the to hit as it can be very decisive at times.
In my example, the target missiles have ECM on them, and the displayed hit chance correctly considered it.

Ah... yes... I saw you wrote that after my post...

But could there be a problem with the log and what it show IF the ECM reduce the to hit below zero... perhaps should test that if that was not done?

Unfortunately, that is not the case. If the expected hit chance is below 0, the AMMs won't auto fire at all.
(https://media.discordapp.net/attachments/619231280713957406/769203067500888124/unknown.png)

AMM:
Code: [Select]
Missile Size: 1.0000 MSP  (2.50000 Tons)     Warhead: 1    Radiation Damage: 1    Manoeuvre Rating: 100
Speed: 20 000 km/s     Fuel: 610     Flight Time: 10 minutes     Range: 11.55m km
Cost Per Missile: 2.5502     Development Cost: 255
Chance to Hit: 1k km/s 2000%   3k km/s 666.7%   5k km/s 400%   10k km/s 200%

Target:
Code: [Select]
Missile Size: 3.00 MSP  (7.500 Tons)     Warhead: 0    Radiation Damage: 0    Manoeuvre Rating: 10
Speed: 40 000 km/s     Fuel: 1 675     Flight Time: 18 hours     Range: 2 556.3m km
ECM Modifier: 60%     ECCM Modifier: 60%
Cost Per Missile: 9.00     Development Cost: 900
Chance to Hit: 1k km/s 400%   3k km/s 133.3%   5k km/s 80%   10k km/s 40%

Hit chance in theory:
20000/40000 - 60% = -10%

Whats interesting here is that it looks like despite deciding not to fire, one of the launchers still had a maintenance failure. Is that WAI?

Edit: Saw the bug report on the bug thread
Title: Re: Anti-missile hit probability
Post by: Iceranger on October 23, 2020, 07:39:18 PM
@Zeebie, I suggest you submit your DB with this bug to the bug report, as we have ruled out the most obvious possibilities...