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> Home > The Corewar Newsletters > Core Warrior > Issue #1

Issue 56                                                     3 March, 1997
______________________________________________________________________________
Core Warrior is a weekly newsletter promoting the game of corewar.  Emphasis
is placed on the most active hills--currently the '94 draft hill and the
beginner hill.  Coverage will follow where ever the action is.  If you have
no clue what I'm talking about then check out these five-star internet locals
for more information:

FAQs are available by anonymous FTP from rtfm.mit.edu as
pub/usenet/news.answers/games/corewar-faq.Z
FTP site is: ftp.csua.berkeley.edu /pub/corewar
Web pages are at: (Please note new Stormking's address)
http://www.koth.org/                            ;Stormking
http://www.ecst.csuchico.edu/~pizza/koth        ;Pizza
http://pauillac.inria.fr/~doligez/corewar/      ;Planar

Newbies should check the stormking page for the FAQ, language specification,
guides, and tutorials.  Post questions to rec.games.corewar.  All new players
are infinitely welcome!

If ftp.csua.berkeley.edu is unreachable, you can download pMARS at:
Terry's web page--http://www.infi.net/~wtnewton/corewar/
Planar ftp site--ftp://ftp.inria.fr/INRIA/Projects/para/doligez/cw/pmars
Fechter ftp site--ftp://members.aol.com/ofechner/corewar

A collection of Bezzi's hints in the first issues is available at:
ftp://ftp.volftp.vol.it/pub/pc/msdos/games/solutions/bbhints.zip

Beppe Bezzi web page - http://www.aspide.it/freeweb/Bezzi
______________________________________________________________________________
Greetings.

Traffic on the hills is very little, and I'm rather busy, so I delayed the
issue. I hope as soon as traffic will come back to old values to begin
publishing CW weekly as usual.
This week we have an interesting hint by Robert Mcrae on hill balance of
power and how much a new warrior, He Scans Alone in the example, will move
the equilibrium.

--Beppe Bezzi
______________________________________________________________________________
Current Status of the Internet Pizza Server ICWS '94 Draft Hill:

Hill Specs:
   coresize: 8000
   max. processes: 8000
   duration: after 80,000 cycles, a tie is declared.
   max. entry length: 100
   minimum distance: 100
   rounds fought: 200
   instruction set: ICWS '94 Draft
 #   %W /  %L /  %T                       Name               Author Score  Age
 1  38.6/ 23.7/ 37.7              Head or Tail    Christian Schmidt 153.5   14
 2  35.4/ 18.1/ 46.5                    RetroQ              P.Kline 152.7   26
 3  38.0/ 26.3/ 35.6            Nine Seven Six           M R Bremer 149.7   90
 4  32.1/ 15.4/ 52.5      Return Of The Jedimp             John K W 148.8  226
 5  35.4/ 23.7/ 40.9                    Gigolo   Core Warrior staff 147.2  280
 6  46.2/ 47.1/  6.7            He Scans Alone              P.Kline 145.2   41
 7  39.5/ 35.6/ 24.8                Tides v0.1          Ian Oversby 143.5   10
 8  32.0/ 21.7/ 46.4           unrequited love                kafka 142.3  324
 9  40.4/ 38.7/ 20.9                NCC-1701-A       Philip Kendall 142.1   29
10  31.0/ 20.7/ 48.4                 Trident^2             John K W 141.3  156
11  39.8/ 38.4/ 21.7              Solomon v0.8          Ian Oversby 141.2   72
12  39.5/ 39.4/ 21.1             QFalcon (vii)          Ian Oversby 139.6   19
13  39.4/ 40.5/ 20.1               The Machine        Anton Marsden 138.2  132
14  32.1/ 26.2/ 41.8              Terkonit 0.4    Christian Schmidt 138.0   32
15  34.0/ 30.3/ 35.7         Fast Fast Fast v2                Franz 137.6   40
16  37.7/ 38.7/ 23.6       Damage Incorporated        Anton Marsden 136.6  267
17  35.5/ 36.0/ 28.5              Scanitator 4    Christian Schmidt 135.1   28
18  27.7/ 20.4/ 51.8               Impish v0.2          Ian Oversby 135.1  265
19  32.7/ 31.3/ 36.0              Instant Ogre                Edgar 134.1    9
20  36.9/ 40.4/ 22.7              Instant Wolf                Edgar 133.4   47
21  41.0/ 49.0/ 10.0                  Memories               Beppe  132.9  140
22  37.7/ 44.4/ 17.8                  Oblivion           Ian Sutton 131.1   91
23  26.2/ 21.9/ 51.9           blue spark 0.04       bjoern guenzel 130.5    6
24  31.1/ 33.5/ 35.4                  Dust 7.0           Justin Kao 128.7    1
25   4.0/  0.0/  0.0                    Test I          Ian Oversby  12.0    2

Monthly age: 13 this month ( 9 last issue, 15 the issue before )
New warriors: 5  Turnover/age rate 38%
Average age: 93 ( 119 last issue, 115 the issue before )
Average score: 135 ( 134 last issue, 138 the issue before )
The top 25 warriors are represented by 15 independent authors: Oversby with
5; Schmidt with 3; Kline, JKW, Marsden and Edgar with 2. All others with one
lonely warrior each.

The fall of Blur2 and Probe, poor Anton :), made the hill much younger. Head
or Tail kept the top spot all time.
______________________________________________________________________________
94 - What's New

 #   %W /  %L /  %T                       Name               Author Score  Age
 3  39.8/ 35.0/ 25.2                Tides v0.1          Ian Oversby 144.5    1
13  32.5/ 32.5/ 35.0              Instant Ogre                Edgar 132.5    1
25  23.2/ 22.1/ 54.7           blue spark 0.04       bjoern guenzel 124.4    1
11  37.4/ 38.8/ 23.8                    Test I          Ian Oversby 136.0    1
25  29.5/ 35.0/ 35.5                  Dust 7.0           Justin Kao 124.0    1

Tides is the only warrior to enter the hill in the top spots.
______________________________________________________________________________
94 - What's No More

 #   %W /  %L /  %T                       Name               Author Score  Age
26   1.9/  0.9/  1.2                 Pulp v0.5          Ian Oversby   7.0    5
26  35.4/ 46.4/ 18.3                     Probe        Anton Marsden 124.4  396
26  24.5/ 26.0/ 49.4                 Eva Peron         David Randel 123.0    8
25  23.2/ 22.1/ 54.7           blue spark 0.04       bjoern guenzel 124.4    1
26  35.1/ 46.4/ 18.5                    Blur 2        Anton Marsden 123.8  403

The two older warriors leave the hill.
______________________________________________________________________________
94 - What's Old

 #   %W /  %L /  %T                       Name               Author Score  Age
 8  29.9/ 21.5/ 48.6           unrequited love                kafka 138.3  324
 5  34.2/ 27.2/ 38.6                    Gigolo   Core Warrior staff 141.2  280
16  35.4/ 41.5/ 23.1       Damage Incorporated        Anton Marsden 129.4  267
19  23.8/ 19.8/ 56.5               Impish v0.2          Ian Oversby 127.8  265
 6  28.8/ 16.9/ 54.4      Return Of The Jedimp             John K W 140.7  226

No new entries, two losses
______________________________________________________________________________
OLD HALL OF FAME
* means the warrior is still active.

Pos    Name                  Author          Age     Strategy
 1  Thermite II            Robert Macrae     2262    Qscan -> bomber
 2  Impfinity v4g1         Planar            1993    Stone/ imp
 3  Jack in the box        Beppe Bezzi       1620    P-warrior
 4  Tornado 3.0            Beppe Bezzi       1567    Bomber
 5  Torch t18              P.Kline           1539    Bomber
 6  Chameleon              Myer R Bremer     1437    P-warrior
 7  Frontwards v2          Steven Morrell    1420    One shot scanner
 8  Evol Cap 6.6           John Wilkinson    1299    Imp / stone
 9  quiz                   Schitzo           1262    Scanner/ bomber
10  T.N.T.                 Maurizio Vittuari 1204    Bomber
11  Grilled Octopus v0.5   David Boeren      1154    P-warrior
12  Hazy Shade II          John Wilkinson    1102    P-warrior
13  Stepping Stone         Kurt Franke       1049    Qscan -> Vampire
14  Rosebud                Beppe Bezzi        993    Stone/ imp
15  Iron Gate 1.5          Wayne Sheppard     926    CMP scanner
16  T.N.T. pro             Maurizio Vittuari  925    Bomber
17  Agony II               Stefan Strack      912    CMP scanner
18  Barrage                Anton Marsden      876    Qscan -> replicator
19  Blue Funk              Steven Morrell     869    Stone/ imp
20  Flurry                 Anton Marsden      835    Qscan -> pwarrior
21  Thermite 1.0           Robert Macrae      802    Qscan -> bomber
22  Blue Funk 3            Steven Morrell     766    Stone/ imp
23  Night Train            Karl Lewin         755    Replicator
24  Mirage 1.5             Anton Marsden      736    Scanner/ bomber
25  Blizzard               Anton Marsden      713    Qscan -> replicator
______________________________________________________________________________
NEW HALL OF FAME
* means the warrior is still active.

Pos    Name                  Author          Age     Strategy
 1  Probe                  Anton Marsden      403    Q^2 -> Bomber
 2  Blur 2                 Anton Marsden      396    Scanner
 3  unrequited love        kafka              324 *  Stone/ imp
 4  Falcon v0.3            Ian Oversby        275    P-warrior
 5  Gigolo                 Core Warrior staff 280 *  Q^2 -> Stone/ imp
 6  Damage Incorporated    Anton Marsden      267 *  Q^2 -> Bomber
 7  Impish v0.2            Ian Oversby        265 *  Stone/ imp
 8  Return Of The Jedimp   John K W           226 *  Q^2 -> Stone/ imp
 9  Rosebud                Beppe              218    Stone/ imp
10  Q^2 Miro               Anders Ivner       214    Q^2 -> Scanner/ bomber
11  Instant Wolf 3.4       Edgar              205    P-warrior
12  Goldfinch              P.Kline            201    P-warrior
13  Simple v0.4b           Ian Oversby        197    Stone/ imp
14  ompega                 Steven Morrell     189    Stone/ imp
15  Frogz                  Franz              172    Paper
16  Trident^2              John K W           156 *  Stone/ imp
17  Memories               Beppe              140 *  Scanner
18  The Machine            Anton Marsden      132 *  Scanner
19  Tiberius 3.1           Franz              130    P-warrior
20  CC Paper 3.3           Franz              107    Paper
21  mrb-test               m r bremer         106    ?
22  T.N.T. pro             Maurizio Vittuari  105    Bomber
23  Jack in the box II     Beppe Bezzi        100    P-warrior

Oblivio and NineSevenSix are near to enter the new HoF
______________________________________________________________________________
Current Status of the Internet Pizza Server Beginner's Hill:

Hill Specs:
         coresize: 8000
   max. processes: 8000
         duration: after 80,000 cycles, a tie is declared.
max. entry length: 100
 minimum distance: 100
      maximum age: At age 100, warriors are retired.
    rounds fought: 200
  instruction set: ICWS '94 Draft

 #   %W /  %L /  %T                       Name               Author Score  Age
 1  51.2/ 38.7/ 10.1             Pentagram 2.a            J.A.Denny 163.8   23
 2  48.1/ 35.3/ 16.7                  Hexagram            J.A.Denny 160.9   21
 3  45.5/ 31.3/ 23.2               Flimsy v0.6          Ian Oversby 159.8   22
 4  49.2/ 41.0/  9.8          Goothmonger v1.2           Ian Sutton 157.3   46
 5  41.1/ 28.8/ 30.0            Scanitator 3.0    Christian Schmidt 153.4   28
 6  43.4/ 33.9/ 22.7           Versatility 1.7   Ross Morgan-Linial 152.9   49
 7  40.7/ 28.7/ 30.6                  Dust 7.0           Justin Kao 152.7    1
 8  40.6/ 29.9/ 29.5                Dust 0.7.5           Justin Kao 151.4   48
 9  46.3/ 43.0/ 10.7            Scankiller 0.1    Christian Schmidt 149.6   33
10  46.1/ 44.0/  9.9   The Stainless Steel Rat    Christian Schmidt 148.1   44
11  43.3/ 39.4/ 17.3      Microsoft Office '96           Justin Kao 147.3   98
12  32.6/ 17.9/ 49.5                DemonSpawn            J.A.Denny 147.2   31
13  44.3/ 43.4/ 12.3             Short Sword 4            JS Pulido 145.2    3
14  41.7/ 38.6/ 19.7       Vivid Radiation 2.0        Matt Lewinski 144.9   70
15  44.0/ 43.1/ 12.9            Flamberge 13.4        Matt Lewinski 144.9   71
16  38.8/ 33.0/ 28.2                    Zorm-B            Anonymous 144.7    6
17  37.9/ 32.0/ 30.0                Apocalypse        Matt Lewinski 143.8   79
18  35.9/ 30.3/ 33.8              Escargot 0.5           Justin Kao 141.5   68
19  32.9/ 27.1/ 40.0                   Quantum    Christian Schmidt 138.8   25
20  41.4/ 45.1/ 13.5      Mostly Harmless v1.1           Justin Kao 137.7   52
21  32.9/ 30.4/ 36.7                 Heartworm                Edgar 135.3   19
22  39.7/ 44.5/ 15.8         Bash the Rat V1.4           Ian Sutton 134.9   63
23  37.3/ 47.2/ 15.5             Dwa Michaly b    Waldemar Bartolik 127.4    9
24  32.2/ 43.1/ 24.8              Time Lag 1c3       Ilmari Karonen 121.3    5
25  33.9/ 51.5/ 14.6             Dwa Michaly a    Waldemar Bartolik 116.4   13

______________________________________________________________________________
The Hint



The Likely Impact of He Scans Alone on the Hill Population

For some time I have been playing with ideas about how populations of warriors 
evolve. I think HSA will have an important impact on the hill, so it seemed 
like a good time to formalise what I've been doing and *test* my views. What 
difference, if any, will HSA make?



Background.

Imagine that we have a hill with very many warriors, all *sharing* a small 
number of public designs. Players are continually trying to get warriors on 
the hill by *selecting* from among those designs, but nothing new is written. 
As new warriors challenge the hill, the population -- or more precisely, the 
proportion of each design in the hill population -- will fluctuate around some 
equilibrium. If you know the scores the warriors average against each other 
you can calculate what it is.

To make it concrete, imagine that all the warriors where copies of Blur, Labo 
or Torn, a scanner, paper and bomber respectively. This table shows the 
average points scored by each against the others, so Blur scores 165 against 
Labo. (For the moment lets ignore the uncertainty due to only having estimates 
of the average scores).

	Blur	Labo	Torn
Blur 	142	165	 99
Labo 	117	101	265
Torn    189	 22	149

>From this you can calculate the "equilibrium" population, which is

	Blur	Labo	Torn
	56.8%	25.0%	18.2%

At equilibrium, every warrior scores equally. In this case, all warriors score 
139.93 points. For example for Blur, 56.8% x 142 + 25.0% x 165 + 18.2% x 99 = 
139.93. (Nearly)

What happens if you deviate from equilibrium? Well, in this case, if you add 
more papers the scanners move to the top of the table and more are added, 
which push off the excess papers. This is a stable equilibrium and the 
population will oscillate around it, never getting too far out of line before 
new warriors arrive to take advantage of the disequilibrium.

Life gets more complicated as the number of designs is increased, because some 
may not be present in the equilibrium at all. This means that you can't get an 
explicit formula for the equilibrium, but you can still simulate easily. Just 
model the hill, run it for several thousands of new submissions and 
"hopefully" it will end up near equilibrium. If you prefer something more 
solid than hope, replicate this process many times with slightly differing 
tables of scores and you obtain a measure of the stability of the equilibrium.

[Theory Note -- I am ignoring potential problems here. In particular it is not 
in general true that there is only 1 equilibrium -- consider a warrior with a 
perfect handshake, but which loses to everything else. It may also be possible 
for non-point equilibria and chaotic behaviour to exist, but I don't think 
this matters too much in practice.]

Phew.

So with a small amount of code (Pascal source and Windows executable 
available) we can take a bunch of warriors and ask which ones would make it 
into the equilibrium. 

The warriors in the equilibrium represent in a compact way the current "state 
of the art". A new warrior pushes the state forward if it makes it into this 
population. Warriors which don't make it can be tested against the population 
to find out by how much they miss, which provides a global ranking in the 
style of Mount Olympus.



So How about HSA?

As a practical example, I took a dozen warriors intended to cover a spread of 
types; for simplicity I ignored P-space and Qscans. I make no great claims for 
the construction of the list, I just picked some of the code I test against. 
My lack of hill-success suggests this set is profoundly flawed :-/

He Scans Alone
Blur 2
Harmony
La Bomba Paper 	Copy
Die Hard Paper 	Copy
D-Clear 	Version (Everyone should have one:)
Rosebud
Impfinity v4g1
Seventyfive
Torch t18
Tornado 3.0 	Copy
Tornado Dat 	Version (Minimalist DAT bomb, DAT clear)

Because I'm really interested in generic types like "bomber" and "paper", I've 
usually just taken the central element, perhaps with a small decoy. "Copy" 
means I've chopped the warrior out of something larger (Apologies to the 
authors for any breakages:) and "Version" means I've adapted it in some way.

This is the resulting score matrix, based on 100 fights.


             H    B    H    L    D   D    R    I   S    T    T    T
HSA    	     150  171  152  177  195 102  141  91  102  171  127  112
Blur         120  142  199  165  97  148  145  212 167  117  132  99
Harmony      146  85   142  130  150 189  110  175 108  103  122  134
La Bomba     111  117  136  101  105 268  102  99  177  118  134  265
Die Hard     93   127  90   99   100 148  103  97  174  132  136  164
D-Clear 1    177  151  111  16   76  150  97   109 186  130  112  102
Rosebud      156  139  173  105  100 181  101  91  212  176  184  187
Impfin v4g1  205  74   112  105  109 175  118  102 195  144  166  223
Seventy5     198  128  189  102  69  114  71   81  150  113  114  201
Torch t18    120  165  181  136  93  154  89   123 167  138  116  135
Tornado 3.0  160  153  164  119  85  181  82   91  174  152  133  155
Tornado Dat  184  189  161  22   74  195  106  49  99   138  134  149

We can now crank the handle on our simulated hill, to obtain the following 
equilibria. To get the following estimates I ran a 10000 rounds on the hill, 
with HSA first excluded and then included. Weights converged to about 4 
decimal places.


		      Pre-HSA	HSA	Score
HSA 			--	18%	140.68
Blur 			39%	29%	140.68
Harmony 		0%	0%	122.77
La Bomba 		14%	6%	140.68
Die Hard 		0%	0%	120.85
D-Clear 1 		0%	0%	127.81
Rosebud 		23%	13%	140.69
Impfin v4g1 		0%	12%	140.69
Seventy5  		0%	3%	140.66
Torch t18 		7%	0%	134.45
Tornado 3.0 		0%	0%	136.56
Tornado Dat 		17%	19%	140.71

The table shows the equilibrium weights Pre- and Post- HSA. The Score column 
shows the score of each warrior post-HSA. Those with weights greater than 0% 
should have identical scores, so the 140.68 to 140.71 range is due to 
incomplete convergence. Those are not in the equilibrium can be ranked on 
their score against the equilibrium warriors, from Tornado 3.0 which is just 
out, to Die Hard and Harmony which are far out.

The above estimates are subject to error due to using only 100 rounds per 
battle to estimate the strength of the warriors. As a test on this 
uncertainty, I ran another 100 trials and in each trial perturbed every score 
by +-10%. This resulted in interquartile spreads of roughly 6.5% for the 
warriors which are in the equilibrium -- for example HSA had a weight of 
between 15.6% and 21.7% half of the time. In practice this means that a 
difference of weights of less than 10% _within_ a column could well be due to 
chance, though we can be more confident about differences _between_ columns. 
This is because a lucky result should benefit a warrior in _both_ tests 
because the same scores were used.

We cannot be confident that Tornado 3.0 is really out of the equilibrium, 
because it entered the equilibrium in 32 of these 100 perturbed trials, but 
Harmony and Diehard never make it in.



Interpretation

Firstly, the warriors not in the equilibrium. It is quite possible that they 
would get in if a different starting set were considered (in particular a set 
containing a high-scoring warrior against which they excel), but against these 
warriors they don't make it.

- Harmony does not waste time carpeting trails but is less effective against 
Silks and loses to anything with SPL bombs.

- Die Hard does not split fast enough to over-write opponents, leading to too 
many draws.

- D-Clear does well against the scanners, but little else.

Secondly, those in or borderline.

- Blur is highly effective and forms a large part of both populations. HSA can 
lose a lot of time bombing Blur's carpet. It also handles Impfinity well. 

- La Bomba is significantly hurt by HSA but is not, as I had feared, 
eliminated. It spreads aggressively enough to score very well against anything 
which can't stun it.

- Impstones overall are little affected; Rosebud is badly hit by HSA but 
Impfinity takes up the slack. Impfinity seems to gain from its phenomenal 
split rate, as hitting anything except the stones does not stun. Even with a 
stone hit, hundreds of further bombs will be thrown by the other. HSA spends a 
lot of time re-carpeting the DJN trails, so the imp-stones of the future want 
messy cores... Hmmm... :)

- The fast bombers as a group just break even, even though with HSA pure 
scanners now comprise a juicy 47% of the population. I suspect the rise of 
Impfinity is what holds back the fast bombers -- the result would have been 
different if I'd just used Rosebud as the generic stone-imp representative. My 
DAT version of Tornado picks up enough against the scanners and rosebud to 
compensate of worse performance against everything else. For the bombers, 
dealing with imps will rise up the agenda and papers will recede somewhat.

- HSA itself takes a significant chunk of the population but it could use a 
tweak against Impfinity. It doesn't replace Blur, partly because once it hits 
a DJN trail it stops scanning and carpets the whole thing. Blur's more casual 
approach to bombing is an advantage when the core is full of rubbish.

Assuming these results hold for hill warriors rather than just the examples 
I've tested, then HSA *is* a substantial step forward. Silks have a major new 
problem. Fortunately HSA's hyper-aggressive bombing ("positive" is the kind of 
term the USAF would use:) makes it particularly vulnerable to decoys and 
trails. Perhaps a stone/silk? Or a fast bomber with a good anti-imp clear? 
Time to get coding...


Regards,  Robert Macrae            ff95@dial.pipex.com
_____________________________________________________________________________
Questions?  Concerns?  Comments?  Complaints?  Mail them to people who care.
authors: Beppe Bezzi <bezzi@nemo.it> or Myer Bremer <bremermr@ecn.purdue.edu>
or Anton Marsden <amarsden@etherspace.gen.nz>
2002-2005 corewar.info. Logo C. Schmidt