[go]$$c Black to play $$ --------------------------------------- $$ | . . . . . . . X O X b X X O O . X O X | $$ | . . . . . . . X O . X O X O O X X O X | $$ | . . . . . . . X O O O O X X X X O O X | $$ | . . . , . . . X , . . O O O O O O X X | $$ | . . . . . . . . X X . . a X X X X X . | $$ | . . . . . . . . . X X X X X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]
Here is a simplified version of a position that happened in my game at the Austin club last night. Black to play, what's the status? Should Black play a, b, or tenuki? Or does it not matter?
Re: Semedori from my game last night
Posted: Wed Aug 17, 2011 1:16 pm
by Chew Terr
By my counting, it's just dead outright. So tenuki or resign, depending on the board.
Re: Semedori from my game last night
Posted: Wed Aug 17, 2011 1:19 pm
by daniel_the_smith
Nice position. Of course the first thing to notice is that black is dead no matter what!
It seems to me that if black plays 'b', he then gets to play 4 dame with sente (while white plays inside his own territory), so I guess 'b' is worth 4 points (+1 because of L15, so 5, I guess). If he starts at 'a', only two dame are sente. Of course tenuki would be correct as long as there are plays larger than four points. 'b' and following is all sente for black, so in theory white won't have time to play reverse sente-- black should play this as late as possible because these moves are also great ko threats.
Edit: Also,
You gave it away by including the word semidori in the title!
Re: Semedori from my game last night
Posted: Wed Aug 17, 2011 1:28 pm
by Magicwand
i will not hide..what is the point? "b" is an endgame (i think 3 point value gote). "a" ia a dame. 0 point value.
so if you have anything bigger than 3 point gote you should tenuki.
Re: Semedori from my game last night
Posted: Wed Aug 17, 2011 1:56 pm
by Bill Spight
$$c Black has a 3 pt. sente $$ --------------------------------------- $$ | . . . . . . . X O X . X X O O 1 X O X | $$ | . . . . . . . X O . X O X O O X X O X | $$ | . . . . . . . X O O O O X X X X O O X | $$ | . . . , . . . X , . . O O O O O O X X | $$ | . . . . . . . . X X . . . X X X X X . | $$ | . . . . . . . . . X X X X X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------
[go]$$Bc $$ --------------------------------------- $$ | . . . . . . . X O X . X X O O b X O X | $$ | . . . . . . . X O 2 X O X O O X X O X | $$ | . . . . . . . X O O O O X X X X O O X | $$ | . . . , . . . X , . . O O O O O O X X | $$ | . . . . . . . . X X . . 1 X X X X X . | $$ | . . . . . . . . . X X X X X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . , . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]
In the game I was Black, and I played . After my hand was moving towards b when I suddenly realized white will not respond to my capture by throwing back in but instead by living independently. My beautiful semedori was ruined!
Another interesting thing is earlier white had a choice between O18 and Q19, and that choice actually makes a difference.
Re: Semedori from my game last night
Posted: Thu Aug 18, 2011 3:43 pm
by Magicwand
Bill Spight wrote:If Black plays sente, the result is -22. (Black gets 1 point at "a".)
yes.. then it is 5 point sente? if not ..where did i count wrong?
Re: Semedori from my game last night
Posted: Thu Aug 18, 2011 4:03 pm
by Bill Spight
Magicwand wrote:
Bill Spight wrote:If Black plays sente, the result is -22. (Black gets 1 point at "a".)
yes.. then it is 5 point sente? if not ..where did i count wrong?
It's a 3 point sente. I think that you counted the 2 points but not the point at "a". Yes?
Re: Semedori from my game last night
Posted: Thu Aug 18, 2011 7:22 pm
by Magicwand
Bill Spight wrote:
Magicwand wrote:
Bill Spight wrote:If Black plays sente, the result is -22. (Black gets 1 point at "a".)
yes.. then it is 5 point sente? if not ..where did i count wrong?
It's a 3 point sente. I think that you counted the 2 points but not the point at "a". Yes?
yes you are correct... i dont know where i cameup with 5 points (i guess i was really tired when i posted that thread)
. After 
my hand was moving towards b when I suddenly realized white will not respond to my capture by throwing back in but instead by living independently. My beautiful semedori was ruined! 
