Completely Artificial Problem / Discussion

lavalyn takes on ANY tsumego regardless of difficulty

The vital point  

lavalyn: I am thoroughly convinced this is the first move of the killing sequences. While my depth and calculation do start failing at around move 12, this is the one I can't refute.

White dies 1  

White dies 2  

White dies 3  

White dies 4  

MattNoonan: I don't see an obvious refutation to this sequence:

White doesn't die 1  

I don't see any way for Black to continue except for a, but then:-

White doesn't die 2  

..but now Black can't play a without b, so White lives.

So a in "White doesn't die 2" seems like a vital point of the shape. What if Black takes it?

White doesn't die 3.a  

White doesn't die 3.b  

White doesn't die 3.c  

..and White gets a ko.

unkx80: Whoa... I thought I solved the problem last night, but actually I did not. Now I *think* I see the solution, so it's a double under the stones problem?

Hmmm... ko ?  

What about this ? --Nando

Lucky

Yes, this is the answer Nando.

Yes, it's a double under the stones problem unkx80.

MattNoonan got the correct sequence but was three moves away from the right answer.

Quite difficult to read it in your head, no? :-)

Nando: definitely ! ;) Thanx Lucky for providing it here :)

unkx80: Thanks for such a nice problem!

MattNoonan: So close! Great problem :)

The vital point  

IwaHanako?: How about as a first move?

The vital point  

unkx80: This lives.

This happened in a game I saw someone play someone else who played in the corner on their first turn.