![]() StartingPoints Languages Aliases (info) Paths Referenced by Homepages
|
Ladder
Path: Tesuji · Prev: DoubleSnapback · Next: Net
Difficulty: Introductory
Keywords: Tesuji, Go term
A ladder (Japanese term: シチョウ shicho, Chinese 征 zheng ) is a technique for capturing stones. At each step the attacker reduces the defender's liberties from two to one. Example
Black
If White tries to escape, Black can at each time play atari and White will be captured.
Clearly White should see this and not play
Ladders may span a large part of the board. If for example Black captures the white stone in a ladder with
If White tries to escape, the ladder will continue in this way. Of course, as it stands, this is a disaster for White. But if there had been a white stone at a, White could now capture a stone and would stand to capture more because of all the double ataris that White can play. Such a stone which stops a ladder from working is called a ladder-breaker.
A simple technique for reading a ladder is to see six diagonal lines from the start of the shicho.[1] Unfortunately SL does not permit me to draw lines, so I have to make do with marking all the points instead. Except for a, b and c, any black stone (only) on the marked points will make a ladder-breaker. However, if there are both black and white stones on the marked points, please read the ladder 'manually': visualise it on the board. That's not so hard, either.
Why is a black stone at a in the previous diagram (the marked stone here) not a ladder-breaker?
This diagram shows why - on the second line, White can play at The reader might want to figure out why having a black stone at b or c in that diagram doesn't make a ladder-breaker. Besides, note that the ladder-breaker points I have marked don't include the points on the first line. Go and figure which of these points make ladder-breakers, and which do not. --unkx80 [1] Dieter: Kageyama says: No shortcuts. Read the ladder. Always. See Practicing Reading Out Ladders. uxs: I agree. Being able to read them out is more useful than this "simple" technique, which apparently doesn't even work when there are just a few stones in the way. On the other hand, reading them out can be hard, especially if you try to read them as "black, white, black, white, ..." You just tend to lose track after a while. I have found that the following works rather well: instead of reading out all stones, just read the inside stones, until you come across possible ladder breakers. In other words, if it's black chasing white stones, read the white ones. This is very easy, since it's just a simple zig-zagging across the board. Then as you come across the possible breaker stones, add (in this example) the black stones. This is also easy, as you just have to add one in the direction where you read the last white stone.
(Actually, you could've allready stopped reading at
(see: Graham, A.C.: Chuang-tzu: the seven inner chapters and other writings: page 186 from the book Chuang-tzu, Unwin Paperbacks, London,1986.)
And another thing I almost forgot to add: practice ! It's not too hard, and it will make you play better. See also:
Path: Tesuji · Prev: DoubleSnapback · Next: Net This is a copy of the living page "Ladder" at Sensei's Library. ![]() |