All you need to know about Carpenter's Square - 12

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

Black 2 wants to use the same attach tesuji. White can simply play White 3 and White 5 , a combination that would not work in the standard Carpenter's square. But because of the defect at White 7 , black's eyespace is reduced and after White 9 the corner is dead in Bulky Five.

Diagram 12.3: Solution 2

White 3 is also possible. Black 4 attempts to reuse the standard solution in Diagram 2.2. However, White 5 is good and black cannot survive.

Diagram 12.4: Solution 3

If black plays Black 2 , white again can exploit the weakness at White 9 to reduce the eyespace. This corner is dead too.

Diagram 12.5: Solution 4

White 5 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.