TsumegoFromGames63/Solution

... normal procedure  

tderz to Rich: ... normal procedure is to continue keeping false eyes false.

... normal procedure  

tderz: One real + 2 false eyes -> dead!

zinger: But now white can run down the left side at a, meaning that some moves down that way will be sente. This would not be the case if was played at to begin with.

... normal procedure(A) ... continuation  

tderz: ... like this?
I thought about this.

... normal procedure(B) ... continuation  

tderz let's compare

... normal procedure(B) ... continuation  

tderz could be also at a (which is weaker)
Is there a big difference between those two diagrams?
Both end with at the same place.
In both cases, White could move to b, but would be enclosed.

Usually I go for shortest sequence, here your proposal seems a better for all those cases where b could mean a connection for White (as Black could play ko at a).

zinger: Yes, it seems the difference is smaller than I thought. Good analysis :)

No connection  

Bill: Now, the original diagram did not show what was on the next line on these diagrams, but let's suppose White has this wall. Now the second variation is the only one to kill.

Of course, in a real game such White strength may be unlikely, but it does illustrate the fact that Black has less to worry about in the second variation, and White has fewer threats to save her stones.

tderz: Thank you Bill. So we can conclude that zinger's wall is just always better, as this wall could as well be created much later, e.g. due to an invasion.
It are those seemingly tiny differences which create chances and set the ground for stronger play. Thanks.

zinger: For the record, it's not really my variation. Walin gave it on the attempts page.

Ko  

tderz: That was the ko, I referred to earlier.
The white -wall is closer to the corner.

Extra aji... Lets live!  

Reuven Actually this wall would change it all... (This page needs a remake >_<)