Double Ladder
Fhayashi -- I've seen this kind of thing pop up a few times during my games, but I haven't seen any references to it...
Anyone care to comment? I guess it shouldn't be much more difficult to read out than a normal ladder, though I find it to be more amusing.
Wouldn't this be what actually happens?
Charles Matthews It seems that both players alternately get the chance to continue the ladders, or to break out themselves using a double atari like this. The situation must be unstable: it can hardly be the case that continuing will be best for both.
Shukan Go, in its 2006-01-30 issue, gave a commentary on the 1st game of the 2006 Kisei match between Hane Naoki and Yamashita Keigo, showing how Black (Yamashita) would be destroyed if he cut with at move 89 and then pulled his stone out with
. Yamashita instead played at the circled point and went on to win the game.
The term double shicho is apparently not used in Japan. Instead the commentary described the sequence as "linked shichos". Sure, I could have read that out.
Another kind of 'Double Ladder'
Sugiuchi Masao, 9p vs. Fujisawa Hosai, 9p
Mentioned in Kageyama Toshiro's Lessons in the Fundamentals of Go as a game that will "go down in the annals of professional play as an all-time freak.".
You can see the complete game at the GoBase Replay Service
( http://www.gobase.org/service/uncgi/bin/replay-sgf?gam=/games/japan/titles/meijin-old/1/game-l46.sgf&off=null).
Dansc: This kind of double ladder is a usual manego breaker, and therefore not really too uncommon. This is the only game in which I've seen this breaker played almost all the way to the end, though.