Late endgame exercise - Fujitsu 4 Game 16

Event: 4th Fujitsu Cup  on Jan van der Steen's web site
Round: Round 2, 8
Date: 1991-04-08
Place: Tokyo (Nihon Ki-in), Japan
Black Player: Cho Hun-hyeon
Black Rank: 9 dan
White Player: O Rissei
White Rank: 9 dan
Komi: 5.5
Result: W+3.5
Source: 1992 Kido yearbook

Position at the end of the game record (move 242). Black to play.  

Captured stones:
B: 1
W: 10

The top-left corner is a seki.

Can Black actually win the semeai in the top-right corner? It doesn't seem possible. Then White should win by 17.5, not 3.5!

Any idea?

Black is dead in the top right, and the score is W+3.5.

Black is dead, basically because in the semeai, White has an eye and Black doesn't (MeAriMeNashi).

To count the score:

White in bottom left: 34 points.
White in top right: 62 points.
White in top middle/left: 2 points.
White's prisoner: 1 points.
Komi: 5.5 points.
White's total: 104.5

Black's territory:

(What a pain, it is all in one lump, which makes it easy to lose count. I'll divide it artifically.)

Black territory, rows 7 and above: 25 points.
Territory from dead white stones in the Black territory: 30 points.
Other Black territory, rows 1 to 6: 36 points.
Black's prisoners: 10 points.
Black's total: 101

(I hope that was comprehensible, everyone has their own way of counting.)

--Tim Hunt

Thanks for the help. I must have done something wrong to get such a big difference. Have to check again. Still, I don't understand why you count 2 points for White in the top left. It's a seki isn't it? The game was played in Tokyo so I suppose Japanese rules were in use.

--jvt

Sorry, I wasn't clear. It is a seki in the top left corner, but there is another white group in the top left quarter of the board, and I was referring to that.

--Tim Hunt

I see. Then White won by 3.5.

--jvt

To answer to the original question : black cannot kill the white group in the upper right corner. It's me ari me nashi, and black has not enough outside liberties.

--lko?