SDK problem from KGS

[Li Kao]

From a game I recently observed on KGS:

$$B Black to move
$$ ---------------------------------------
$$ . . . . . . . O . . . . .
$$ . . . X . . . . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B Black to move
$$ ---------------------------------------
$$ . . . . . . . O . . . . .
$$ . . . X . . . . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .[/go]

While at first glance it looked alive I read a ko. Hope I didn't miss some sequence which makes white live
[sgf-full](;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[White]PB[Black]AW[ja][kb][hc][ic][jc][hd][jd][he][ie][je]AB[fb][lb][ec][gc][kc][gd][kd][md][ge][ke][hf][if][jf]
;B[la]
(;W[ha]
;B[ka]
;W[ib]
;B[jb]
;W[gb]
;B[ia])
(;W[ib]
;B[ka]
(;W[gb]
;B[ga]
;W[ha]
;B[hb])
(;W[hb]
;B[ha]
;W[gb]
;B[ga]))
(;W[hb]
;B[jb]
;W[ib]
;B[ka]
(;W[ha]
;B[jb])
(;W[gb]
;B[ga]
;W[ha]
;B[jb]))
(;W[gb]
;B[ka]
(;W[ib]
;B[ga]
;W[ha]
;B[hb])
(;W[ha]
;B[jb]
;W[ib]
;B[ia])))[/sgf-full]

[daniel_the_smith]

Hidden from those who want to treat it as a status problem:

Unless I'm mistaken, white is unconditionally dead if black moves first.

IOW Li Kao missed some things ^^

[Li Kao]

Unless I'm mistaken, white is unconditionally dead if black moves first.

I didn't read very careful for black since I was happy to find at least a ko. Some other observers thought it had a real eye there, so I read mainly to disprove life. Guess I need to read again for black^^

[illluck]

I must be missing something too, because I also read it as ko.

[Sverre]

I also read out a ko. I can't find a way for Black to kill unconditionally.

$$B I believe this B1 fails, 5 and 6 are miai
$$ ---------------------------------------
$$ . . . . 4 1 . O 6 3 . . .
$$ . . . X 5 2 . . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B I believe this B1 fails, 5 and 6 are miai
$$ ---------------------------------------
$$ . . . . 4 1 . O 6 3 . . .
$$ . . . X 5 2 . . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .[/go]

$$B B1 and a are both defeated easily.
$$ ---------------------------------------
$$ . . . . 1 . . O . . . . .
$$ . . . X . a 2 . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B B1 and a are both defeated easily.
$$ ---------------------------------------
$$ . . . . 1 . . O . . . . .
$$ . . . X . a 2 . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .[/go]

That leaves only this .

$$B Doesn't white make ko here?
$$ ---------------------------------------
$$ . . . . . 2 . O 3 1 . . .
$$ . . . X . . 4 . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .

Click Here To Show Diagram Code

[go]$$B Doesn't white make ko here?
$$ ---------------------------------------
$$ . . . . . 2 . O 3 1 . . .
$$ . . . X . . 4 . O X . . .
$$ . . X . X O O O X . . . .
$$ . . . . X O . O X . X . .
$$ . . . . X O O O X . . . .
$$ . . . . . X X X . . . . .
$$ . . . . . . . . . . . . .[/go]

[Koroviev]

Tried hard on this and can't find a move for black that gets better than a ko?