All you need to know about Carpenter's Square - 12
Submitted by macelee on 2013-01-24 13:07; Last upda
ted on: 2018-11-17 17:05
Diagram 12.1: White to play
As will be shown, the missing stone at the hoshi point is a major defect for black.
Diagram 12.2: Solution 1
wants to use the same attach tesuji. White can simply play 
and 
, a combination that would not work in the standard Carpenter's square. But because of the defect at 
, black's eyespace is reduced and after 
the corner is dead in Bulky Five.
Diagram 12.3: Solution 2
is also possible. 
attempts to reuse the standard solution in Diagram 2.2. However, is good and black cannot survive.
Diagram 12.4: Solution 3
If black plays , white again can exploit the weakness at to reduce the eyespace. This corner is dead too.
Diagram 12.5: Solution 4
is also possible. Shown here is a different way to form Bulky Five.
Conclusion: this corner is very weak with the missing stone at hoshi point. There are a number of other ways to kill this corner. I will leave the readers to practice and find them all.
