Problem 11460 goproblems.com


Author	Dimitre	Created	2008-07-13
Difficulty	6 kyu (history)	Source	One of my KGS games.
AVG solve time	78 sec	Stars	3.2 (20 votes)
User attempts	1053 / 2645	Collections	Cutting, Prevent the Connection, Amateur Game, Corner based
Genre	tesuji ⓢ	Your attempts	N/A
Similar problems
Created	2008-07-13
Source	One of my KGS games.
Stars	3.2 (20 votes)
Collections	Cutting, Prevent the Connection, Amateur Game, Corner based
Your attempts	N/A

(;AB[iq]AB[jq]AB[kr]AB[lr]AB[mr]AB[lq]AB[mo]AB[mn]AB[nn]AB[oo]AB[pp]AB[mp]AW[kq]AW[jp]AW[ko]AW[lo]AW[lp]AW[no]AW[np]AW[nq]AW[mq]AW[nr]AW[qn]AW[qq]TR[mq]TR[nq]TR[np]TR[no]TR[nr]C[Black to capture the marked stones.]AP[goproblems] (;B[pq] (;W[pr]C[CHOICE] (;B[qr] (;W[rr]C[CHOICE] (;B[or] (;W[qs]C[CHOICE] (;B[os]C[This works. And White cannot start a ko at P1.RIGHT]) (;B[ns]C[];W[os]C[White can start an unfavorable ko, black can do better.])) (;W[ps]C[CHOICE] (;B[os]C[RIGHT]) (;B[ns]C[RIGHT]) (;B[oq];W[os];B[ns];W[ms];B[ls]C[];W[ns]C[White escapes.]) (;B[ms];W[ns] (;B[oq];W[os]) (;B[op];W[os])))) (;B[qs];W[rs];B[or];W[ps];B[os];W[oq]C[White escapes.])) (;W[qs]C[CHOICE] (;B[rr];W[rq];B[rs] (;W[os]C[CHOICE];B[ps];W[or];B[qp];W[qs];B[rp]C[Black not only kills the marked stones, but gets the corner as well.RIGHT]) (;W[sr]C[CHOICE];B[ps];W[or];B[qp];W[os];B[rp];W[qs];B[sq]C[Right.RIGHT])) (;B[or];W[rr] (;B[os]C[This works. And White cannot start a ko at P1.RIGHT]) (;B[ns]C[];W[os]C[White can start an unfavorable ko, black can do better.])))) (;B[or];W[os];B[qr];W[oq] (;B[rq];W[qp];B[qo];W[rp];B[ro]C[Black not only kills the marked stones, but gets the corner as well.RIGHT]) (;B[qp]C[];W[rq];B[rr];W[rp];B[ro] (;W[qo]C[CHOICE] (;B[sp]C[Black not only kills the marked stones, but gets the corner as well.RIGHT]) (;B[sq]C[Black not only kills the marked stones, but gets the corner as well.RIGHT])) (;W[po]C[CHOICE] (;B[qo];W[pn] (;B[on]C[];W[rn];B[sp];W[qk]C[Bigger corner for Black and White makes some points on the side.RIGHT]) (;B[op] (;W[on]C[CHOICE] (;B[sp]C[This is too conservative. S6 does more for Black.]) (;B[sq]C[This is too conservative. S6 does more for Black.]) (;B[rn]C[More favorable than playing T3 or T4.RIGHT])) (;W[rn]C[CHOICE] (;B[on];W[so] (;B[sp];W[sq];B[sr]C[Yes.RIGHT]) (;B[sq]C[RIGHT])) (;B[so];W[on]C[] (;B[sp];W[sn];B[sq]C[Works, but gote.RIGHT]) (;B[sq];W[sn];B[sp]C[Works, but gote.RIGHT])) (;B[sn];W[on];B[so];W[sm];B[sq];W[sp]C[Very, very wrong.]) (;B[sp];W[on] (;B[sq]C[RIGHT]) (;B[so])) (;B[sq];W[on]C[] (;B[so]) (;B[sp]C[RIGHT]))))) (;B[sp];W[on] (;B[qo];W[op]C[White escapes.]) (;B[op];W[qo]C[Wrong.]) (;B[sq];W[op]C[White escapes.])) (;B[sq];W[on] (;B[qo];W[op]C[White escapes.]) (;B[sp];W[op]C[White escapes.]) (;B[op];W[qo]C[Wrong.])))) (;B[rr];W[po] (;B[op];W[qp];B[on];W[rq] (;B[ms];W[ns] (;B[ps];W[qs];B[rs];W[sr]C[Just ko]) (;B[rs];W[sr]) (;B[sr];W[rs];B[qs];W[sq]C[Seki])) (;B[qs];W[sr]) (;B[sr];W[rs] (;B[ms];W[ns];B[qs];W[sq]C[Seki]) (;B[qs];W[sq];B[ms];W[ns]C[Seki])) (;B[ps];W[qs];B[ms];W[ns];B[rs];W[sr]C[Just ko])) (;B[qp];W[on];B[op]C[RIGHT])))) (;W[ps]C[CHOICE] (;B[os] (;W[pr]C[CHOICE];B[or];W[oq];B[qr];W[ns];B[rq];W[qp];B[qo];W[rp];B[ro]C[Black not only kills the marked stones, but gets the corner as well.RIGHT]) (;W[or]C[CHOICE];B[pr] (;W[qs]C[CHOICE];B[qr]C[RightRIGHT]) (;W[ns]C[CHOICE] (;B[qs];W[qr];B[os]C[Ko for White to escape.]) (;B[qr]C[Black gets the corner as well.RIGHT])))) (;B[or];W[os] (;B[qr];W[pr] (;B[oq];W[rr];B[ns];W[ms];B[ls]C[];W[ns]C[White escapes.]) (;B[rq]C[Black gets the corner as well.RIGHT]) (;B[qs];W[oq];B[rq]C[RIGHT];W[qp];B[qo];W[rp];B[ro]C[Black not only kills the marked stones, but gets the corner as well.RIGHT])) (;B[pr];W[qr]C[White connects.])) (;B[qs];W[qr]C[No good.]) (;B[pr]C[RightRIGHT]) (;B[qr]C[RightRIGHT]))) (;B[oq] (;W[or]C[White escapes.CHOICE]) (;W[pr]C[CHOICE];B[or];W[os];B[op];W[ns];B[ms];W[ps];B[pq];W[qr]C[White escapes.])) (;B[or];W[oq] (;B[pq];W[pr]C[] (;B[qr] (;W[os]C[CHOICE] (;B[qp];W[rq];B[rr];W[rp];B[ro] (;W[qo]C[CHOICE] (;B[sp]C[Black not only kills the marked stones, but gets the corner as well.RIGHT]) (;B[sq]C[Black not only kills the marked stones, but gets the corner as well.RIGHT])) (;W[po]C[CHOICE] (;B[qo];W[pn] (;B[on]C[];W[rn];B[sp];W[qk]C[Bigger corner for Black and White makes some points on the side.RIGHT]) (;B[op] (;W[on]C[CHOICE] (;B[sp]C[This is too conservative. S6 does more for Black.]) (;B[sq]C[This is too conservative. S6 does more for Black.]) (;B[rn]C[More favorable than playing T3 or T4.RIGHT])) (;W[rn]C[CHOICE] (;B[on];W[so] (;B[sp];W[sq];B[sr]C[Yes.RIGHT]) (;B[sq]C[RIGHT])) (;B[so];W[on]C[] (;B[sp];W[sn];B[sq]C[Works, but gote.RIGHT]) (;B[sq];W[sn];B[sp]C[Works, but gote.RIGHT])) (;B[sn];W[on];B[so];W[sm];B[sq];W[sp]C[Very, very wrong.]) (;B[sp];W[on] (;B[sq]C[RIGHT]) (;B[so];W[sn];B[sq]C[Works, but gote.RIGHT])) (;B[sq];W[on]C[] (;B[so];W[sn];B[sp]C[Works, but gote.RIGHT]) (;B[sp]C[RIGHT]))))) (;B[sp];W[on] (;B[qo];W[op]C[White escapes.]) (;B[op];W[qo]C[Wrong.]) (;B[sq];W[op]C[White escapes.])) (;B[sq];W[on] (;B[qo];W[op]C[White escapes.]) (;B[sp];W[op]C[White escapes.]) (;B[op];W[qo]C[Wrong.])))) (;B[rq];W[qp];B[qo];W[rp];B[ro]C[RIGHT])) (;W[ps]C[CHOICE] (;B[qs];W[os];B[rq];W[qp];B[qo];W[rp];B[ro]C[Black not only kills the marked stones, but gets the corner as well.RIGHT]) (;B[rq]C[Black gets a corner as well.RIGHT]) (;B[ns];W[os];B[op];W[ms];B[ls];W[rr];B[ns];W[qs];B[or];W[qp]C[It works.RIGHT]))) (;B[rq];W[qp];B[qo];W[rr];B[rp];W[qr];B[ro];W[os])) (;B[pr])) (;B[pr];W[pq];B[oq];W[or];B[os];W[op];B[ns];W[oq]C[White escapes.]) (;B[ns];W[pq]C[White escapes.]) (;B[os];W[pq]C[White escapes.]))