Problem 4256 goproblems.com


Author	Warp	Created	2004-04-14
Difficulty	1 kyu (history)	Source	KGS game
AVG solve time	80 sec	Stars	3.5 (10 votes)
User attempts	720 / 3352	Collections	Corner based
Genre	life and death ⓢ	Your attempts	N/A
Similar problems
Created	2004-04-14
Source	KGS game
Stars	3.5 (10 votes)
Collections	Corner based
Your attempts	N/A

(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2] RU[Japanese]SZ[19]KM[0.00] PW[White]PB[Black]AW[di][aj][bj][cj][ak][dk][ek][fk][al][bl][fl][fm][gn][co][fo][ho][jo][dp][ep][fp][gp][aq][cq][br]AB[bk][ck][cl][dl][el][am][bm][em][cn][en][fn][ao][bp][bq][eq][fq][gq][hq][jq][kq]LB[ao:2][co:3][aq:1]C[Black to play and save all his stones.] (;B[bo]CR[bo] ;W[dn]CR[dn] (;B[cp]CR[cp] ;W[do]CR[do] (;B[cr]CR[cr] ;W[cm]CR[cm] (;B[dm]CR[dm] ;W[eo]CR[eo] (;B[cm]CR[cm] ;W[an]CR[an] (;B[bn]CR[bn] ;W[dq]CR[dq] (;B[dr]CR[dr] ;W[ar]CR[ar] (;B[bs]CR[bs]C[RIGHT]) (;B[as]CR[as] ;W[bs]CR[bs] ;B[cs]CR[cs] ;W[er]CR[er]) (;B[er]CR[er] ;W[ap]CR[ap])) (;B[bs]CR[bs] ;W[ar]CR[ar] (;B[dr]CR[dr]C[RIGHT]) (;B[cs]CR[cs] ;W[dr]CR[dr]) (;B[as]CR[as] ;W[cs]CR[cs] (;B[dr]CR[dr] ;W[ap]CR[ap]) (;B[bs]CR[bs] ;W[dr]CR[dr])) (;B[ds]CR[ds] ;W[dr]CR[dr] (;B[cs]CR[cs] ;W[es]CR[es]) (;B[er]CR[er] ;W[cs]CR[cs])) (;B[er]CR[er] ;W[dr]CR[dr]))) (;B[dq]CR[dq] ;W[bn]CR[bn])) (;B[dq]CR[dq] ;W[cm]CR[cm])) (;B[dq]CR[dq] ;W[dm]CR[dm]) (;B[bn]CR[bn] ;W[dm]CR[dm])) (;B[dq]CR[dq] ;W[cm]CR[cm] (;B[cr]CR[cr] ;W[dm]CR[dm]) (;B[dm]CR[dm] ;W[eo]CR[eo] (;B[cr]CR[cr] ;W[cm]CR[cm]) (;B[cm]CR[cm] ;W[an]CR[an] (;B[cr]CR[cr] ;W[bn]CR[bn]) (;B[bn]CR[bn] ;W[cr]CR[cr] (;B[ar]CR[ar] ;W[dr]CR[dr] (;B[er]CR[er] ;W[as]CR[as] (;B[ds]CR[ds] ;W[cs]CR[cs]C[Seki is not good enough]) (;B[cs]CR[cs] ;W[ds]CR[ds] ;B[es]CR[es]C[Seki is not good enough.]) (;B[es]CR[es] ;W[ar]CR[ar]) (;B[bs]CR[bs] ;W[cs]CR[cs] ;B[es]CR[es] ;W[ar]CR[ar] ;B[ds]CR[ds]C[Seki is not good enough.])) (;B[ap]CR[ap] ;W[bs]CR[bs] ;B[er]CR[er] ;W[ds]CR[ds] ;B[es]CR[es]C[Seki is not good enough.]) (;B[bs]CR[bs] ;W[cs]CR[cs] (;B[er]CR[er] ;W[as]CR[as] ;B[es]CR[es] ;W[ar]CR[ar] ;B[ds]CR[ds]C[Seki is not good enough.]) (;B[ap]CR[ap] ;W[as]CR[as] ;B[er]CR[er] ;W[aq]CR[aq]C[Two-step ko]))) (;B[dr]CR[dr] ;W[ar]CR[ar]))))) (;B[dr]CR[dr] ;W[cr]CR[cr] ;B[dq]CR[dq] ;W[ar]CR[ar])) (;B[dm]CR[dm] ;W[do]CR[do] (;B[cp]CR[cp] ;W[dq]CR[dq]) (;B[dq]CR[dq] ;W[cp]CR[cp])) (;B[dq]CR[dq] ;W[cp]CR[cp]) (;B[cm]CR[cm] ;W[cp]CR[cp]) (;B[eo]CR[eo] ;W[do]CR[do])) (;B[cp]CR[cp] ;W[bo]CR[bo]) (;B[ap]CR[ap] ;W[cp]CR[cp] (;B[bo]CR[bo] ;W[dn]CR[dn]) (;B[ar]CR[ar] ;W[cr]CR[cr] (;B[bo]CR[bo] ;W[dn]CR[dn]) (;B[dn]CR[dn] ;W[bo]CR[bo]) (;B[do]CR[do] ;W[bo]CR[bo])) (;B[do]CR[do] ;W[bo]CR[bo]) (;B[dn]CR[dn] ;W[bo]CR[bo]) (;B[bn]CR[bn] ;W[bo]CR[bo])) (;B[do]CR[do] ;W[bo]CR[bo] (;B[cp]CR[cp] ;W[ap]CR[ap]) (;B[bn]CR[bn] ;W[cp]CR[cp]) (;B[eo]CR[eo] ;W[cp]CR[cp] (;B[bn]CR[bn] ;W[dm]CR[dm]) (;B[dm]CR[dm] ;W[bn]CR[bn])) (;B[dq]CR[dq] ;W[cp]CR[cp]) (;B[ap]CR[ap] ;W[cp]CR[cp]) (;B[dm]CR[dm] ;W[cp]CR[cp])) (;B[dn]CR[dn] ;W[bo]CR[bo]) (;B[dq]CR[dq] ;W[cp]CR[cp]) (;B[cr]CR[cr] ;W[bo]CR[bo] (;B[bs]CR[bs] ;W[cm]CR[cm] (;B[dm]CR[dm] ;W[dn]CR[dn] (;B[do]CR[do] ;W[eo]CR[eo] (;B[an]CR[an] ;W[dn]CR[dn] (;B[cm]CR[cm] ;W[bn]CR[bn]C[Ko]) (;B[bn]CR[bn] ;W[cm]CR[cm]) (;B[ap]CR[ap] ;W[cm]CR[cm]) (;B[ar]CR[ar] ;W[cm]CR[cm])) (;B[cm]CR[cm] ;W[bn]CR[bn] (;B[an]CR[an] ;W[dn]CR[dn]C[Ko]) (;B[dn]CR[dn] ;W[an]CR[an]) (;B[ap]CR[ap] ;W[dn]CR[dn]C[Ko]) (;B[ar]CR[ar] ;W[dn]CR[dn]C[Ko])) (;B[bn]CR[bn] ;W[dn]CR[dn]C[Ko]) (;B[dn]CR[dn] ;W[bn]CR[bn]) (;B[ap]CR[ap] ;W[bn]CR[bn] (;B[an]CR[an] ;W[dn]CR[dn]C[Ko]) (;B[dn]CR[dn] ;W[cm]CR[cm]) (;B[cp]CR[cp] ;W[an]CR[an]) (;B[cm]CR[cm] ;W[dn]CR[dn]C[Ko]) (;B[ar]CR[ar] ;W[dn]CR[dn]C[Ko]) (;B[dq]CR[dq] ;W[dn]CR[dn]C[Ko])) (;B[ar]CR[ar] ;W[bn]CR[bn] (;B[an]CR[an] ;W[dn]CR[dn]C[Ko]) (;B[dn]CR[dn] ;W[cm]CR[cm]) (;B[cm]CR[cm] ;W[dn]CR[dn]C[Ko]) (;B[ap]CR[ap] ;W[dn]CR[dn]C[Ko]) (;B[dq]CR[dq] ;W[dn]CR[dn]C[Ko]) (;B[cp]CR[cp] ;W[dn]CR[dn]C[Ko]))) (;B[bn]CR[bn] ;W[eo]CR[eo]C[Ko]) (;B[an]CR[an] ;W[eo]CR[eo] ;B[do]CR[do]C[Ko. (If black has no good threats he will have to connect at C7, after which white B6 makes the ko severe.)])) (;B[dn]CR[dn] ;W[bn]CR[bn] (;B[an]CR[an] ;W[ap]CR[ap]) (;B[dm]CR[dm] ;W[an]CR[an]) (;B[ap]CR[ap] ;W[an]CR[an]) (;B[ar]CR[ar] ;W[an]CR[an]) (;B[do]CR[do] ;W[an]CR[an])) (;B[do]CR[do] ;W[bn]CR[bn] (;B[dm]CR[dm] ;W[cp]CR[cp] (;B[ar]CR[ar] ;W[an]CR[an]) (;B[ap]CR[ap] ;W[an]CR[an]) (;B[an]CR[an] ;W[ap]CR[ap])) (;B[an]CR[an] ;W[ap]CR[ap]) (;B[cp]CR[cp] ;W[ap]CR[ap]) (;B[dn]CR[dn] ;W[an]CR[an]) (;B[dq]CR[dq] ;W[cp]CR[cp]) (;B[ar]CR[ar] ;W[an]CR[an])) (;B[bn]CR[bn] ;W[dn]CR[dn] (;B[dm]CR[dm] ;W[eo]CR[eo]C[Ko]) (;B[ap]CR[ap] ;W[an]CR[an]) (;B[ar]CR[ar] ;W[an]CR[an]) (;B[an]CR[an] ;W[ap]CR[ap]) (;B[cp]CR[cp] ;W[ap]CR[ap])) (;B[an]CR[an] ;W[bn]CR[bn] (;B[dm]CR[dm] ;W[eo]CR[eo] (;B[ap]CR[ap] ;W[dn]CR[dn]C[Ko]) (;B[dn]CR[dn] ;W[do]CR[do]) (;B[do]CR[do] ;W[dn]CR[dn]C[Ko]) (;B[cm]CR[cm] ;W[dn]CR[dn]C[Ko])) (;B[dn]CR[dn] ;W[ap]CR[ap]) (;B[ap]CR[ap] ;W[cp]CR[cp]) (;B[ar]CR[ar] ;W[ap]CR[ap]))) (;B[ap]CR[ap] ;W[dr]CR[dr] (;B[ar]CR[ar] ;W[cs]CR[cs] (;B[cp]CR[cp] ;W[do]CR[do] (;B[dq]CR[dq] ;W[cr]CR[cr] (;B[er]CR[er] ;W[bn]CR[bn] ;B[an]CR[an] ;W[cm]CR[cm] ;B[dm]CR[dm] ;W[dn]CR[dn]C[Ko]) (;B[an]CR[an] ;W[cm]CR[cm] (;B[dm]CR[dm] ;W[bn]CR[bn] ;B[er]CR[er] ;W[dn]CR[dn]C[Ko]) (;B[bn]CR[bn] ;W[dn]CR[dn] ;B[dm]CR[dm] ;W[eo]CR[eo]) (;B[dn]CR[dn] ;W[bn]CR[bn] ;B[dm]CR[dm] ;W[eo]CR[eo])) (;B[bn]CR[bn] ;W[dn]CR[dn] (;B[er]CR[er] ;W[cm]CR[cm] ;B[dm]CR[dm] ;W[eo]CR[eo]) (;B[cm]CR[cm] ;W[dm]CR[dm] ;B[er]CR[er] ;W[eo]CR[eo]) (;B[an]CR[an] ;W[cm]CR[cm] ;B[dm]CR[dm] ;W[eo]CR[eo]))) (;B[an]CR[an] ;W[dq]CR[dq])) (;B[dq]CR[dq] ;W[cp]CR[cp])) (;B[bs]CR[bs] ;W[cs]CR[cs] ;B[ar]CR[ar] ;W[cr]CR[cr]) (;B[cp]CR[cp] ;W[an]CR[an]) (;B[dq]CR[dq] ;W[cp]CR[cp] (;B[an]CR[an] ;W[cs]CR[cs]) (;B[ar]CR[ar] ;W[cs]CR[cs])) (;B[an]CR[an] ;W[cp]CR[cp]) (;B[do]CR[do] ;W[cp]CR[cp])) (;B[ar]CR[ar] ;W[as]CR[as] (;B[ap]CR[ap] ;W[dr]CR[dr]) (;B[dq]CR[dq] ;W[cp]CR[cp]) (;B[dr]CR[dr] ;W[cp]CR[cp]) (;B[an]CR[an] ;W[dr]CR[dr])) (;B[dq]CR[dq] ;W[cp]CR[cp]) (;B[bn]CR[bn] ;W[cp]CR[cp]) (;B[an]CR[an] ;W[cp]CR[cp] ;B[ap]CR[ap] ;W[dr]CR[dr])))