From news-rocq.inria.fr!jussieu.fr!math.ohio-state.edu!uwm.edu!vixen.cso.uiuc.edu!newsrelay.iastate.edu!dunix.drake.edu!acad.drake.edu!pk6811s Wed Nov 8 11:58:03 1995 Article: 2823 of rec.games.corewar Path: news-rocq.inria.fr!jussieu.fr!math.ohio-state.edu!uwm.edu!vixen.cso.uiuc.edu!newsrelay.iastate.edu!dunix.drake.edu!acad.drake.edu!pk6811s From: pk6811s@acad.drake.edu Newsgroups: rec.games.corewar Subject: Re: myZizzor Date: 7 Nov 95 09:19:44 CST Organization: Drake University, Des Moines, Iowa Lines: 62 Distribution: world Message-ID: <1995Nov7.091944@acad.drake.edu> NNTP-Posting-Host: acad.drake.edu myZizzor is a very nice, simple warrior with a nice, simple solution that goes back to the earliest days of core wars. First there were bombers, then there was... Gemini! The first bombers used small, positive increments, and did not use a djn stream. Gemini's strategy was to copy itself forward and jump to the new copy at a rate that kept just ahead of the bombing run. Evenually it would overwrite the bomber and kill it. The same strategy works against myZizzor with this more modern, redundant version: ;redcode-94m quiet ;name test ;kill test ;strategy gemini - jump ahead of scanning/bombing run ; start spl 1 ; spl 1 ; make 8 processes spl 1 ; spl g2 g1 spl @0,43 ; jump to next location mov }g1,>g1 ; move code there mov 2,>1 ; little bombing dat 1,28 for 4 dat 1,1 rof for 50 dat 1,1 rof g2 spl @0,43 ; jump to next location mov }g2,>g2 ; move code there mov 2,>1 ; little bombing dat 1,28 for 4 dat 1,1 rof end start myZizzor forward scans with a step of 8 which is faster than we are jumping, but once he finds the first abandoned copy he is reduced to a .3c carpet bomber with which we can keep up. Hopefully one of the two copies will overrun myZizzor before he goes into the sweep/djn process. Once he starts clearing we do keep ahead of the forward clear, but that backward djn sometimes gives trouble. Once people starting experimenting with larger bomb steps, Gemini was doomed. And then came mice... There are other solutions to myZizzor such as backward scanning with a step of 9. In general when two opponents are of similar size and scanning with small step sizes in opposite directions (one backward, the other forward) the one with the larger step will always win. Future pspacers might find it useful to include a combination forward/ backward scanner using a medium step size as a sort of anti-body mechanism against this class of opponents. Just run it until it loses. Paul Kline pk6811s@acad.drake.edu