Aloha.

Mahalo.

THERE'S BARELY a game that does not feature a ladder somehow. But the threat is stronger than the execution, so that very, very few are played out. This article surveys several games from the GoGoD database where the ladder did materialise. There is a separate article on the origin of the term "ladder" and its Japanese version shichou.

Misreads
One of the alternative renderings mentioned in the above separate article seems apposite here: dead birds. Sick as a parrot may be how a pro feels when he's misread a ladder. It's pretty rare anyway, but even rarer to admit to it.

In 1952-06-04a Yamabe Toshiro misread a ladder (after Black 72) against Kitani Minoru in the Oteai. We know that only because the Fukumenshi (Yomiuri go reporter) Yamada Torakichi bumped into him on the steps of the Nihon Ki-in on his way out. Yamabe just said, "I resigned." Yamada had the wit not simply to offer commiserations and replied, "Bit early isn't it? What on earth..." Yamabe then unburdened himself just enough: "I must be mad. I misread a ladder so there's nothing to talk about."

In 1994-01-06c Rin Kaiho misread his White 80 against Takemiya Masaki in the 33rd Judan. He didn't say so but that was the pro opinion led by Oya Koichi and Nakayama Noriyuki in the press room. Nakayama was a late arrival and not initially aware of who was playing. Apparently he took one look at the scorekeeper's diagram to know that one side was Takemiya. But White 80 merited a double-take.

2000-05-24a was Game 1 of the 55th Honinbo title match between O Meien v Cho Sonjin. It was O who blundered but at least he went on to win the title for the first time.

Most unusual ladder breaker
When ladders do surface in pro play, the action is nearly always to do with ladder breakers rather than the ladder itself. The game 1978-05-11e is our nomination for the most unusual ladder breaker. Kato Masao played Black 29 against Hashimoto Utaro. But White 34 was a most surprising move to leave the ladder working, too.

Double ladder breakers
Moves that break two ladders simultaneously have a long history. The famous Pressing the Divine Head position was reputed to be such a move discovered by a top Chinese player in Tang times to defeat a visiting "prince" from Japan. 1996-01-31a - Kobayashi Satoru vs Cho Chikun is a modern example, and another flawed but intersting example is in a game between Masubuchi Tatsuko and Yasunaga Hajime when Muasubuchi was on the verge of becoming pro (1922-07-00b). It is flawed because Black 61 should have been at 73, winning at once, and because White 60 should have been at 77.

Manego ladders
One unusual pro use of a ladder is in breaking a mane-go (mimic go) strategy. 1977-12-07a betweeen Hanawa Yasutoki and Nakayama Noriyuki shows this feature. Of course, no mention of mane-go should omit Fujisawa Hosai and we can see the ladder tactic in game 1961-09-13a against Sugiucho Masao.

There are a couple more examples in 1987-12-11a, Cho Hun-hyeon against Chang Tu-chin (not played out here but still relevant) and 1963-11-04a, Sakata Eio against Fujisawa.

Playing out the ladder unexpectedly
Probably the most interesting and spectacular examples are those where the ladder is played out unexpectedly. A player deliberately plays out the ladder knowing that he will lose it (the chased stones will connect up safely), but he reckons that he can get enough compensation from the surrounding position. Such games are not quite as rare as hen's teeth. In fact, for one example we can go back as far as 1740hcem241, where the great master Shi Dingan gave four stones to Zhang Zhenxi. This repays study: did Shi resign and if so was it too soon? Either way it was a quite brilliant conception.

Old Chinese games turn up lots of marvellous things. 1850JQXG494, the monk Qiuhang against Shen Jiezhi, is another fascinating example. A modern Chinese example is 1982-12-11a.

Instinctively, perhaps, we may feel that such things are not likely to occur among modern pros playing each other. If so, what about 1974-06-10b, Seo Pong-su against Cho Hun-hyeon in the exalted arena of the 6th Myeongin Final? The tactic was reckoned to work here as there was enough compensation for the ladder loser.

1983-10-19f, an all-female affair between Shinkai Hiroko and Tanimiya Ayoko in the Japanese Oteai, is worth noting. We'll come to why in a second. 1999-12-19a was noteworthy in that it was a rare example from international play: Game 3 of 1st Nong Shim Cup between Kudo Norio of Japan and Mok Chin-seok of Korea. But for the purists, Kudo's conception was flawed in that he could simply play a normal breaker to achieve his goal.

In 2002-04-06a, Yi Seong-chae against Weon Seong-chin in the 7th Ch'eonweon, the idea certainly was flawed because the compensation just wasn't big enough.

Now for a case where the idea paid off big time. In 2003-04-23a Yi Se-tol caught Hong Chang-sik by surprise in a KAT Systems Cup semi-final. It was a brilliant plan, and this probably was the first ladder game to become famous on the internet. However, it was precisely the ability of fans worldwide to discuss this game instantly on the internet that made this game so celebrated. Yet the conception seems strongly redolent of the barely known Shinkai-Tanimiya game, so the purists may not want to give it a full 10 out of 10 for artistic merit. Still, it's a real beauty.

There is a nice example of rescuing a dead group by playing out a ladder in 2002-04-25n - Zhong Wenqing was the insightful player this time, against Zhang Weijin in the Chinese National Team Tournament.

A further example of playing out a broken ladder was provided by Bernd Schmidt: 1989-07-06b: Ishida Yoshi vs Takemiya Masaki.

A new form of duelling
Was it James Thurber who came up with the gags about settling disputes: submarines at 30 yards, or dirty words at forty paces? Anyway, how about two ladders fighting each other? 1953-03-05a, Takagawa Kaku against Sakata Eio, makes for an amusing finale.

And, finally, a ladder used for threats in the oldest form of duel, the ko fight. Game 1998-09-27b is between two Korean youngsters who were then still amateurs but were on the verge of turning pro. [Surce: GoGoD Encylopaedia]

We need a collective noun for ladders! Any suggestions?

The following is an article from the GoGoD Encylopaedia which lists various interesting ladder situations. The formatting is lost in the transfer here, and you will need the GoGoD database for the games, but I don't think you'll find a bigger XXXX of ladders.

We need a collective noun for ladders! Any suggestions?

We need a collective noun...

I really like the Lee Sedol ladder game but it seems to me that the common description is a bit off? (maybe I'm just a pedant)

Click Here To Show Diagram Code

[go]$$B Valid ladder capture?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . . O X X . . . . . . . . X . . . . . |
$$ | . . . O . X . . . , . . . . . X . . . |
$$ | . . O O . . . . . . . . . . . . . . . |
$$ | . . O X X . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . X . |
$$ | . . . . . . . . . . . . . . X . X O . |
$$ | . . . . . . . . . . . . . X . X . O O |
$$ | . . . . . . . . . . O . O X X O O O . |
$$ | . . . . . . . . . . . . O O O X X X O |
$$ | . . O . . . . . . . . X X X X O O X O |
$$ | . . . , . . . . . , . . O . . O O X . |
$$ | . . . O . . . . X . . . . X X X O X X |
$$ | . . . . . . . . . . . . . . . . O O X |
$$ | . . . . . . . . . . . . . . . . . O . |
$$ ---------------------------------------[/go]

It seems to me that the ladder is working for black on the basis that black has forcing moves against the bottom right situation that he would rather not play out but can be played out at (almost) any time.
If black plays out the moves ahead of time they are loss making so Lee would rather get away without making the exchanges. Black shouldn't need to make these exchanges to capture in the ladder.

{snip}

White misreads and thinks that the ladder is not working and so tries to pull out the stone. Black is happy to keep it captured in the ladder.
As white compounds the mistake by playing out the ladder and making this obligation heavier and heavier, at some point it becomes better to save the ladder stones than to save all of white's corner stones - At this point I would say that the ladder is no longer working as the ladder making moves wouldn't be sente. I'm not sure what point this is but I'm guessing Katago could probably help answer that by testing out some variations where each player takes the trade at different points?