Teire/Attempts2

Sub-page of Teire

Problem 2

[Diagram]

Problem 2

Where must Black play te-ire?


[Diagram]

underlying problem

tderz: once the liberty at black+circle is gone,
White can capture at least the 4 left stones by atari-ing at W1.

Having said this,
any black stone at at any of the points occupied by W1 to W5,
or those a, b, which would pt W2, W5 in atari,
would defend against this threat.

[Diagram]

defending moves

tderz: thus, the possible defending moves are: a to g.

Of these, g looks the least attractive,
b the most dangerous (3 ko threats);
a looks quite ok, as one is relatively safe from an attack at p (rests peep c with possible false eye b).
c has one 2 threats (f, d);
f might be in danger after peep c, then jump to p (defense b, q might cost points).

My conclusion: best answer depends on surrounding & actual game situation.

Bill: Yes, but don't you think that a will usually be best? d still allows two ko threats.

[Diagram]

defending moves

tderz: yes, normally agreed, as snapback-test W2 can be answered by B3 (direct life), even if a white stone is present at circle.
Usually it depends on the actual game situation.

[Diagram]

snapback-test -> false eye aji

tderz: this W2 allows for making a false eye if white+circle is safe.

[Diagram]

not biggest - safest life

tderz: Hence, sometimes B1 could be safest (even in the presence of an white+circle -> Black has 2 eyes at f and d)


tderz: I was wondering why this found an entry at teire.


This is a copy of the living page "Teire/Attempts2" at Sensei's Library.
(OC) 2009 the Authors, published under the OpenContent License V1.0.
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