(FT)Canna get the archives to divulge this...

7 posts ยท Jan 13 2005 to Jan 18 2005

From: Inire <inire@y...>

Date: Thu, 13 Jan 2005 12:41:56 -0800 (PST)

Subject: (FT)Canna get the archives to divulge this...

hey all-

my group typically plays using the vector movement system, and as such are
using the 3mu radius dictated for missile attacks. The question:

If missile attacks have ben truncated in Vector, have
PDS/ADFC also been changed, or is the defence side of
the equation 'getting a deal'? If the latter, what has been the rationale (so
i can go to my people and explain the logic).

If this is covered at the NIFT site i haven't found it yet, so i apologize in
advance for any oversight on my part.

TIA

-j

From: Oerjan Ohlson <oerjan.ohlson@t...>

Date: Thu, 13 Jan 2005 22:42:24 +0100

Subject: Re: (FT)Canna get the archives to divulge this...

> Inire wrote:

> If missile attacks have ben truncated in Vector, have

No. ADFC range is 6mu in both Vector and Cinematic.

> or is the defence side of the equation 'getting a deal'?

No. The reduction of the missiles' target acquisition range prevents the

*missiles* from getting a very good deal in Vector.

> If the latter, what has been the rationale

The ships' manoevering envelope is much smaller in Vector than it is in
Cinematic, so a 6mu-radius circle would give the missiles a much higher
hit probability in Vector than it does in Cinematic. Reducing the missiles'
Vector target acquisition range to 3mu cuts them back to about the same hit
probability in Vector as they have in Cinematic.

Regards,

From: Thomas Westbrook <tom_westbrook@y...>

Date: Thu, 13 Jan 2005 18:29:09 -0800 (PST)

Subject: Re: (FT)Canna get the archives to divulge this...

--- Oerjan Ohlson <oerjan.ohlson@telia.com> wrote
> No. The reduction of the missiles' target

MT missles DO NOT have the OPTIONAL, as I read it, reduced acquision range and
are harder to knock down.

> The ships' manoevering envelope is much smaller in

I thought the OPTIONAL reduction more for the more
predictable trajectory, or so - A moot point right
now.
Though I read somewhere, don't recall off-hand, that
the Kravak Gravatic engines

> missiles a much higher hit

The actual probability of SM hitting a ship with a PDS is about zero percent
on average (I did the analysis), reardless of movement type. A point for a
later discussion as I am currently bloodying (now that I have time) Laser's HM
test rules.

From: Laserlight <laserlight@q...>

Date: Thu, 13 Jan 2005 22:14:19 -0500

Subject: Re: (FT)Canna get the archives to divulge this...

ThomasW said
> The actual probability of SM hitting a ship with a PDS

Either you've left something out, or this is going to be an interesting
analysis.

> discussion as I am currently bloodying (now that I

Not mine, I just posted them. The original was from a better Brain than mine.

From: Oerjan Ohlson <oerjan.ohlson@t...>

Date: Fri, 14 Jan 2005 18:33:39 +0100

Subject: Re: (FT)Canna get the archives to divulge this...

> Thomas Westbrook wrote:

> No. The reduction of the missiles' target

The updated "MT missiles" (aka "Heavy Missiles") have the same reduced
acquisition range as SMs do once they've finished their 2ndary move, and

are *easier* for PDS to shoot down than an entire SM salvo.

> The ships' manoevering envelope is much smaller in

It is optional, but as the rule says this option is "strongly suggested".

> more for the more predictable trajectory, or so

That's what I said, and it was a near-verbatim quote from FB1. The
"manoeuvre envelope" for a specific ship is the the smallest volume
encompassing all trajectories that ship can follow, so the smaller the
manoeuvre envelope is the fewer trajectories the ship has to choose between
and thus the more predictable its movement will be.

And going back to Inire's question, the motivation for reducing the SMs'

target acquisition range to 3mu in Vector is explicitly given in FB1
immediately after the rule itself:

"SPECIAL NOTE if you choose to use the VECTOR MOVEMENT system given in this
book instead of the "standard" FT movement rules, then we strongly suggest
redusing the attack radius of Salvo Missiles from 6" to 3" - this will
prevent the missiles becoming too accurate against the more predictable
manoeuvre envelope of a vector-movement ship. ..."

(FB1 p.9, 2nd paragraf)

> Though I read somewhere, don't recall off-hand, that

Looks like you didn't finish this sentence, but I know what you're thinking of
anyway: it is the sentence immediately after the above quote. You're
misremembering it, though - that bit is not about the Kra'Vak Advanced
drives (which use the same movement system as human/Phalon standard
drives) at all; instead it is about how to justify using different target
acquisition ranges in games where some ships use *Cinematic* movement while
others use *Vector* movement (eg. EFSB-style Babylon 5 battles).

> missiles a much higher hit

Is that the same analysis you presented in your very first post to this list
(September 2nd
<http://lists.firedrake.org/gzg/200409/msg00032.html>), where you
claimed the very same thing? If so, it was very badly wrong; I pointed out the
flaws in it in my reply the same day you posted it
(<http://lists.firedrake.org/gzg/200409/msg00048.html>). If you have
updated your analysis and still get the same completely false "about zero
percent on average" result, you're welcome to post it here so we can check
where you went wrong this time.

The actual probability of an SM salvo inflicting damage on a target is the
product of the probabilities of two separate events: the probability that it
will acquire the target at all (ie., that the target ends its movement within

the salvo's target acquisition range), and the probability that at least

one of the salvo's missiles will make it past the target's PDS.

The first of these, the probability that the salvo will acquire a target,
depends mainly on the target's thrust rating and the two players' respective
skills. As such it is difficult to analyze other than by empirical means, ie.
by keeping records during games and counting how large a fraction of the
launched salvoes that actually locked on to something;

but it is definitely larger than zero percent :-/

The second is the probability that at least one of the salvo's missiles will
make it past the target's PDS, and this seems to be the one you believe is
"about zero percent on average" even for a ship with "a PDS"
-
ie., *one single* PDS (unless of course this is a second case of your
interpreting "a" as meaning "any number of"). This iis incorrect; the
probability that an SM salvo opposed by one single PDS will inflict at least
some damage on the target is 87%. That's quite far from "about zero percent on
average".

If the salvo is opposed by 2, 3 or 4 PDSs this probability drops to 74%,

61% or 50% respectively; even if the target manages to mass 10 PDSs against
this single SM salvo there's still an 8.5% chance that at least one of its
missiles will get through. Of course 8.5% isn't very much (only one in
twelve), but 10 PDSs against a single salvo is a *lot* - and little
though it is, 8.5% is nevertheless quite a bit more than your "about zero
percent on average".

Regards,

From: Thomas Westbrook <tom_westbrook@y...>

Date: Mon, 17 Jan 2005 14:29:35 -0800 (PST)

Subject: Re: (FT)Canna get the archives to divulge this...

I don't use Heavy Missles, when refering to MT missiles I mean MT missles out
of the More Thrust Book, and not from any other source.

I blantelty refuse to use anything based on Salvo Missiles.

> --- Oerjan Ohlson <oerjan.ohlson@telia.com> wrote:

From: Oerjan Ohlson <oerjan.ohlson@t...>

Date: Tue, 18 Jan 2005 06:40:51 +0100

Subject: Re: (FT)Canna get the archives to divulge this...

> Thomas Westbrook wrote:

> > The updated "MT missiles" (aka "Heavy Missiles")

Fine; in that case they are able to choose specifically which target within
6mu and outside the missile's (A) arc they want to attack and are *still*
easier for PDS to shoot down than an entire SM salvo are since *PDS* (as

opposed to *PDAF*) hits MT missiles on 4+.

Regards,