_PUSH OFF_ A midweek review of Corewar September 29, 1993 ------------------------------------------------------------------------------- I. The Standings: # %W/ %L/ %T Name Author Score Age 1 40/ 31/ 29 QuickFreeze v1.4 P.Kline 150 8 2 45/ 44/ 11 Iron Gate 1.01 Wayne Sheppard 146 247 3 34/ 24/ 42 Deck of Many Things c w blue 143 7 4 45/ 48/ 8 Agony 6.0 Stefan Strack 142 56 5 44/ 46/ 11 Dragon Spear c w blue 142 1206 6 39/ 38/ 24 Winter Werewolf 3 W. Mintardjo 139 422 7 42/ 45/ 13 Impurge Fredrik Ohrstrom 138 428 8 33/ 27/ 40 FlyPaper 3.0 J.Layland 138 528 9 40/ 42/ 18 Beholder's Eye v2 W. Mintardjo 137 24 10 42/ 48/ 9 Backstabber Anders Ivner 136 2 11 35/ 37/ 28 Herem VI Anders Ivner 134 276 12 29/ 25/ 46 Impact v1.0 Anders Ivner 133 241 13 29/ 26/ 45 Hydra Stephen Linhart 133 173 14 34/ 36/ 30 Keystone t13 P.Kline 132 62 15 30/ 27/ 43 ttt nandor sieben 132 328 16 36/ 41/ 23 Leprechaun 1b Anders Ivner 130 172 17 26/ 23/ 51 pMARS pMARS project 129 153 18 28/ 26/ 46 Imprimis 7 P.Kline 129 344 19 28/ 29/ 43 Night Crawler Wayne Sheppard 128 1104 20 38/ 51/ 11 Cleaver Wayne Sheppard 126 1 21 27/ 28/ 45 Sphinx v2.8 W. Mintardjo 125 2102 ------------------------------------------------------------------------------- II. The Basics: -Core War Archives, including many helpful articles, warrior source code, and reliable emulators, are available via anonymous FTP at soda.berkeley.edu in pub/corewar. -FAQ for this newsgroup is available via anonymous FTP at rtfm.mit.edu as pub/usenet/news.answers/games/corewar-faq.z ------------------------------------------------------------------------------- III. The Scoop: ** EXTRA ** EXTRA ** EXTRA ** EXTRA ** EXTRA ** EXTRA ** EXTRA ** Today saw the ever-durable Sphinx v2.8 pushed off KotH, at the record age of 2102. After A. Ivner's "Backstabber" dropped *all* the imps to the bottom ranks, W. Sheppard's "Cleaver" finished the job - barely - by a single point nosing Sphinx off the Hill. KotH now awaits the 'imp'roved Sphinx, which has been flexing its muscles in the wings, faster launch, offset boot, unique stone and all! Is this a conspiracy or what :-) All the other imp-authors are holding their breath to see who's next for the chop, since all are firmly settled in the bottom rankings (Imprimis nooo!) ***************************************************************************** It happened last October! A mighty wind swept the Hill. Brave and hardened warriors were whisked away like paper dolls. Imps were back, and this time they meant business! The Corewar world watched in dismay as Anders Ivner's "The IMPire strikes back" dismantled such valiant fighters as "Charon", "No Mucking About", "B-scanners live in vain", and "Sucker". Even venerable "Flash Paper" dropped in the rankings. As Ivner put up test after test afficionados marveled at his ;strategy line: "What is the optimal setup?". Imps? There were no imps on KotH. Imps can only tie and ties only bring 1 point. After basking in the glory a day or so, Ivner posted his source, and we all pondered the fact that fast imps only tie, but slow imps can kill you. Here is a report from October 13, 1992: # %W/%L/%T Name Author Score Age 1 40/11/49 The IMPire strikes back Anders Ivner 169 1 2 47/42/10 No Mucking About Campbell Fraser 152 596 3 38/28/34 Atomic Sheep c w blue 149 54 4 45/45/ 9 nandor sieben 146 383 5 33/23/44 dead end nandor sieben 144 20 6 36/30/34 Chaff v2.8 Patrick Hunt 142 107 7 43/44/13 Falling Leaf 1.21 Matt Hastings 142 734 8 34/26/41 Flash Paper3.7 Matt Hastings 142 648 9 42/43/15 testing Roadrunner S. Halvorsen 140 440 10 41/41/18 Pale Shears Matt Hastings 140 385 11 43/46/11 Charon v7.0 J.Cisek & S.Strack 139 244 12 42/47/11 Sucker 4 Stefan Strack 138 849 13 41/45/14 Dain7 1 Dan Nabutovsky 137 14 14 40/44/16 B-scanners live in vain Matt Hastings 136 578 15 36/38/26 Smooth Noodle Map 6 Matt Hastings 135 400 16 39/44/17 Gimli Dan Nabutovsky 135 10 17 38/42/20 SNAKE Wayne Sheppard 134 5 18 40/46/14 Twilight Pits 3 W. Mintardjo 133 86 19 38/46/16 Eclipse v3.0 P.Kline 131 67 20 42/53/ 5 Orc c w blue 130 117 A quick scan down the loss column tells the story. IMPire was not yielding any losses. If he wasn't beating you he was stealing your wins with ties. Authors scrambled to unravel this mystery. Better and faster imp-launchers appeared. Something called 'imp-gates' were uncovered in the archives, dusted off, and tacked into programs. A new form made its appearance - the stone-imp combination, shortly followed by the vampire-imp. Here is a report from October 20, 1992 - one week later: # %W/%L/%T Name Author Score Age 1 38/12/50 Impression 1 Dan Nabutovsky 164 19 2 35/13/52 Red Dragon c w blue 156 6 3 43/38/19 Beholder's Eye v1.1 W. Mintardjo 148 41 4 39/34/27 Winter Werewolf W. Mintardjo 145 25 5 45/45/10 test Stefan Strack 145 2 6 33/22/45 The Sender of Eight Matt Hastings 143 47 7 43/45/12 Emerald P.Kline 141 17 8 38/36/26 a B-scanner Darkly Matt Hastings 141 9 9 25/10/64 repimp nandor sieben 141 30 10 33/27/41 Atomic Sheep c w blue 139 175 11 32/28/40 Tarrasque c w blue 135 10 12 40/50/11 sproba nandor sieben 130 8 13 33/37/29 Pale Shears2 Matt Hastings 129 26 14 37/45/19 Dain Dan Nabutovsky 129 16 15 35/43/22 A CMP-Scanner Darkly Matt Hastings 128 12 16 23/20/57 The IMPire strikes back Anders Ivner 126 70 17 37/48/15 Eclipse 2.0 P.Kline 126 1 18 38/50/12 nandor sieben 125 504 19 34/48/17 Charon v7.0 J.Cisek & S.Strack 121 365 20 33/52/15 No Mucking About Campbell Fraser 113 717 Compare the age columns from these reports and you will see how great the "impact" of this new warrior-form. Programs that had been on the Hill for months had vanished. Some 'imp'ortant facts: The standard form of the imp-spiral is: a mov 0,b b mov 0,c c mov 0,d ... n mov 0,a+1 where a,b,c,...n are equidistant in core and execute in the above order. After n, the process at a advances to a+1 and executes. Attacking a single point in the spiral only kills it if it is his turn to execute, or if it is the trailing process (a). And if you are overrun by the spiral while executing fewer processes than he is, you will outrun him and die. There are 1224 imp-numbers in a core size of 8000. Since all mod-one steps are imp-numbers, there are no core sizes (larger than 2) which support no imp-spirals. Any prime number which is not a factor of the core size would be an imp-number. Some interesting imp-numbers are: #pts imp# (#pts and imp# can be interchanged) 1 1 (8001) 3 2667 7 1143 9 889 11 5091 13 3077 17 2353 19 7579 31 3871 63 127 2571 2571 7981 429 (the largest) To find imp-numbers, solve for N in both of these equations: 1. (J*coresize + 1) mod N = 0 2. (J*coresize + 1) / N < coresize where J is any positive integer. I once wrote a 3-point launcher that calculated its imp-number at startup, so it would work on any core size. What did I call it? "Improvise" of course! Unfortunately in many core sizes, 3 is not an imp-number. However it may be possible to do a startup search for imp-sizes up to 13 (which would cover all core sizes up to 30030), and guarantee an imp-launch. While much progress has been made in combatting imps, it appears they are here to stay, just like paper, stone, and scissors. By adding forms to the mix on KotH, however, it becomes harder for new programs to break in - they just don't have a large advantage against enough forms to create a sufficiently high score. You might have a great scanner-killer but there aren't enough scanners out there to boost your score. So new programs may need multiple strategies to make it on KotH. And adding a spiral may be an attractive option :-) **************************************************************************** On a non-imp topic, we can't overlook the passing of Grimm's Vampyre at the respectable age of 282. With Grimm's goes the last vampire on the Hill (as far as I can tell :-) Also, welcome back to S. Morrell and Imps! Imps! Imps!. ------------------------------------------------------------------------------- IV. The Outlook: 5 43/ 47/ 9 Backstabber Anders Ivner 140 1 6 30/ 24/ 46 Deck of Many Things c w blue 137 1 ------------------------------------------------------------------------------- V. The Quick Look: 16 23/ 15/ 63 Imps! Imps! Imps! Steven Morrell 131 1 16 29/ 29/ 43 NC Test Wayne Sheppard 129 1 20 38/ 51/ 11 Cleaver Wayne Sheppard 126 1 21 0/ 78/ 22 SPL-Bomb Slava Shinderov 22 0 21 2/ 54/ 44 SPLIMP v1.1 Remy A. G. Wetzels 49 0 21 2/ 56/ 42 PiggyBack 0.2 Ben Byer 47 0 21 5/ 67/ 28 pb bb 44 0 21 14/ 39/ 47 Thundering buttocks J Horwich 90 0 21 15/ 68/ 17 Nosferatu 0.21 J Kyle Kelso 63 0 21 16/ 28/ 56 Sauron v3.0 Michael Constant 103 0 21 16/ 48/ 36 spriteII Cormac Walsh 85 0 21 17/ 27/ 56 sub-type-something or oth c w blue 106 0 21 17/ 58/ 25 All That Glitters v2.1 Mike Nonemacher 76 0 21 17/ 61/ 22 Imperor VII Pierre Baillargeon 74 0 21 19/ 40/ 41 Tangle 1.0 Devin Kilminster 99 0 21 19/ 77/ 4 Test Ray Cromwell 60 0 21 21/ 18/ 60 Wriggler III Geoff Rehmet 124 0 21 21/ 21/ 59 Wriggler II Geoff Rehmet 120 0 21 22/ 24/ 54 Red Baron v3.3 Mike Nonemacher 121 0 21 22/ 69/ 10 Morticia v1.0 Mike Nonemacher 75 0 21 24/ 34/ 42 Hunger Pangs Steven Morrell 115 0 21 26/ 64/ 11 Cat v2.0 Tim Scheer 88 0 21 28/ 52/ 21 bugII shaun 103 0 21 32/ 51/ 16 Sunburst 31 Jay Han 113 0 21 36/ 49/ 15 Grimm's Vampyre c w blue 123 0 21 39/ 52/ 9 Tiny Gate Wayne Sheppard 126 0 ------------------------------------------------------------------------------- VI. The Hint: On Killing Imps. Oh yes, they can be killed. Here are some of the ways. 1. Gates. Gates. Gates. Say again. Gates. Gates. Gates Here is the form W. Mintardjo used in Beholder's Eye and Winter Werewolf: gate equ example-10 example spl 0,