Re: Followup to Operation Furious Riposte [FB KV speculations]

Thomas Barclay wrote in a heavily formatted post which showed up as 14
kB of blank space until I had replied, saved the reply and re-opened
it:

> To Oerjan:
> I like your thoughts. Increase the costs. That might just do the
trick.
> I'll try some of your figures. Though I have to ask how on a per mass
> basis you can equate RG to beams... given that a beam 1 or beam 2 has
> a range of 12 or 24 MU and a class 1 and 2 RG have a 30" range.

6 mu isn't a very long distance if the initial vectors were in opposite
directions. IME it is only important if the KV manages to stay in that
6mu range band for several turns - which is possible given their high
maneuverability, but not very easy.

> That means
> that your small ships are ineffective for a turn or more while the KV
> are "in the zone".
> 
> I believe this summarizes the average damage:
> Beam	   RB1	      RB2     RB3
> 1	   0.8	       --      --
> 2	   1.6	       0.8     --
> 3	   2.4	       1.6     0.8

Which *per Mass*, which is the only valid comparision (if your weapon
is twice as big as mine, I'm able to bring two of my weapons to the
fight against your single one), turns out to be

Beam	Arc	RB1	RB2	RB3
1	  6	0.8	  --	  --
2	  3	0.8	0.4	  --
3	  1	0.6	0.4	0.2
3	  3	0.4	0.27	0.13

against unscreened targets. Multiply by 0.792 vs level-1 screens/KV
armour and by 0.583 vs level-2 screens/KV armour.

> Whereas RG (to compare, I've average groups of 2 6" RB to produce a
> composite result)
> 
> RG	  RB1	      RB2	RB3
> 1	  1.0	      0.55	0.1
> 2	  2.25	      1.27	0.24
> 3	  3.71	      2.12	0.39

The average damage *per Mass*, averaged in the same way, is

RG	RB1	RB2	RB3
1	0.5	0.27	0.06
2	0.75	0.42	0.08
3	0.75	0.42	0.08

> I think we can see clearly that at any range, RG are better.

Only if you can "clearly see" that 0.8 < 0.75. I can't see that, I'm
afraid.

As you can see, the C1 and C2 beams inflict *more* damage per mass
against unscreened/armoured targets in RB1, and C2s (and single-arc
C3s) are very close in RB2. Single-arc C3 batteries actually outgun
railguns in RB3, again on a per-Mass comparision - even against level-2
armour.

Had it not been for the fact that KV railguns ignore screens, they
would  actually have been *overpriced* at 4*Mass.

> But more particularly, they are PRONOUNCEDLY better at RB2

4% higher average damage against unscreened/armoured targets... that's
not a significant difference. The initiative rolls have a bigger effect
on the outcome of the battle than a 4% higher average damage per Mass.

It becomes significant when the KV armour is factored in, but the KV
armour isn't part of the railguns and should therefore be evaluated
(and paid for) separately.

> and RB3 where all but class 3 beams are very ineffective. 

In RB3, narrow-arc C3 beams (such as the one on the Furious) hold their
own fairly well - on average 0.2 damage per Mass vs unscreened targets,
0.16 vs level-1 screen/armour (compared to 0.17 for the larger RGs to
range 30, or 0.08 for the entire RB), and 0.13 vs level-2
screens/armour.

> RG of class 2 or 3 are still very effective in RB2, and can be quite
> effective out in RB 3.

On a per-mass reading, well... OK, they're some 30% better than the
RG1, but that doesn't say too much :-/ 0.08 damage per Mass 

> We can't compare maximum damage, because of beam rerolls, 

Of course not. That's why we compare average damages.

> but a class 3
> railgun (if it rolls a 6 at 30") then a 3 on the dice, will do six
> points. Not that hard to do.

You'll do it on average one time out of nine, or 11% of the time.
Another 5.6% of the time you'll inflict only three points, and the
remaining 83.3% of the time the RG3 doesn't inflict any damage at all.

> For a class 3 beam to do that kind of damage, it needs to roll either
three > sixes to start with or at least one six and some other good
numbers 
> followed by some other good numbers. It just doesn't happen that
often. 

On the other hand, it will inflict *some* damage at least 33% of the
time even against level-2 armour/screens (50% of the time against
unscreened targets) - ie, it is much less dependent on your rolling a
"6" on that critical first roll. It needs it to inflict lots of damage,
but it isn't totally ineffective if you don't get that "6".

> So it seems likely that with some
> luck, a class 6 RG is significantly more dangerous than an equivalent
> beam (fewer die rolls, regresses less to mean results).

At short ranges, the RGs regresses less. At long ranges (where you need
to roll high on the first die to inflict any damage at all), it
regresses more than the beams instead.

> So I'm not sure how you can say whether the RG costs are good or ill.

You look at the average die rolls, and when you've done that you can
look at the standard deviations if you're still not sure of what you
see. 

It is as simple as that - no different from comparing pulse torps to
beams, and considerably easier than comparing SMs or MTMs to beams
(missile hit probabilities are purely a function of player skill, and
that's not very easy at all to quantify statistically :-/ ).

> I wonder what the impact of removing size class as a modifier for the
> doubled damage. It slightls the big guns a bit, but it would
certainly
> prevent someone building a class 5 railgun which would always do 10
> points when it hit... that's a scary mechanic that does not scale
well.

It does scale well provided that you set its Mass properly (should be
Mass 10 to balance vs the smaller RGs). The real problem is what you do
with Class-6 and bigger RGs - do they inflict 3x damage if they roll 12
or better? <g>

If you remove the size class modifier for doubled damage, you adjust
their Masses accordingly. As simple as that.

> Your comments on the armour and hull appear quite valid. I think the
> general observation is either the ships need toned down or they need
> cost increased.

The end result is the same. Less bang for the bucks :-/

> Your comment on reducing scattergun effectiveness against other ships
> I find appealing also.

I don't think I've posted that one for... must be four years or so  -
last time was in one of the "how to fix the MT Kra'Vak" debates back
when Adam was list admin.

> Then they are still a nasty but temporary fighter
> defence, but they'll deter scouts from whacking destroyers and the
like.
> 12" of lethality versus ships is just nasty. If we dropped the result
by
> 1 per full 2" (-1 at 2" to -6 at 12"), then we'd have a weapon still
> nasty against fighters, and nasty against ships the KV are good
enough
> or lucky enough to get beside, but not so lethal against anything in
a
> 24" diameter sphere!

Yep. In MT, I used -1 per full 2mu vs starships and -1 per full 1mu vs
fighters, but that was before the ADFC. -1 per 2mu vs anything is
simpler, of course <g>

Regards,

Oerjan Ohlson
oerjan.ohlson@telia.com

"Life is like a sewer.
  What you get out of it, depends on what you put into it."
- Hen3ry