howard@cpocd2.UUCP (Howard A. Landman) (10/17/87)
I've been playing around with the Go program developed for the Mac by Jim Logan at BYU under Lynn Beus. The version I have is "Go V1.0B4". First the bug. The final score reported when you select "Final Score" from the "Display" menu is wrong. Actually, both Japanese and Chinese scores are reported, and they are both wrong. In some cases, the program reports a negative Chinese score, which is impossible. I think this has something to do with the score being updated incorrectly when you use the mouse to remove dead stones at the end of the game; perhaps under some circumstances empty points inside dead groups are being subtracted once too often. A friend sent me source code to an older version of the program, so if I can figure it out I'll post a diff to fix the bug later. Other than that, the program is pretty nice. It seems to be somewhere between 20 and 40 kyu. I'm shodan, and I've never lost against it yet even giving a 17 stone handicap, and in several even games it failed to keep any stones alive at all. But it's relatively fast: about 1 second per move at search depth 1 & width 1; about 4 seconds per move at width 2 and depth 2; on up to a maximum allowed width of 5 and depth of 7, which takes forever. The deeper searches don't improve play by much, so I stick with 2x2 most of the time. Some things the program understands: Atari Capturing How to cut & connect (but not when) Hane & connect on the edge Ko (somewhat) The 3rd line, 3-3 point Peeping Some things the program doesn't understand: Making 2 eyes Keeping enough eyespace for 2 eyes Snapbacks (at low lookahead depth) Monkey jumps Importance of central influence How to use thickness When atari should be ignored The program is public domain. If anyone wants a copy, send me mail and we'll work something out. I would also be interested in opinions on whether I should consider posting the program, if so whether binary or source or both and in what newsgroup(s). The binary is just over 100 KB on the Mac. The (older) source is about 84 KB. Note to Anders, and others working on Go file formats: the program's file format uses 10 or 11 bytes per move, plus some header. Weren't we arguing a while back about whether 3 or 4 bytes was too much, compared to the 2 bytes in Anders' proposal? Anyway, a typical first two moves might be stored as "add b C,4\radd w Q,16\r" ('\r' is carriage return, a.k.a. CTRL-M, not newline). -- Howard A. Landman {oliveb,hplabs}!intelca!mipos3!cpocd2!howard <- works howard%cpocd2%sc.intel.com@RELAY.CS.NET <- recently flaky "Unpick a ninny - recall Mecham"