Problem 4708 goproblems.com


Author	santa c	Created	2004-06-27
Difficulty	7 dan (history)	Source	GZP middle 189
AVG solve time	74 sec	Stars	3.71 (7 votes)
User attempts	156 / 1514	Collections	Instruction Required, GuanZiPu, Corner based
Genre	life and death ⓒ	Your attempts	N/A
Similar problems
Created	2004-06-27
Source	GZP middle 189
Stars	3.71 (7 votes)
Collections	Instruction Required, GuanZiPu, Corner based
Your attempts	N/A

(;AB[bc]AB[cc]AB[dd]AB[ed]AB[ec]AB[eb]AW[fb]AW[fc]AW[fd]AW[fe]AW[ee]AW[de]AW[cd]AW[bd]AW[bf]AW[cf]C[White can't let black live - No matter what! Find the best ko! (Seki isn't good enough!)]AP[goproblems] (;W[db];B[da] (;W[ca];B[ea] (;W[bb];B[ab] (;W[cb];B[ba];W[aa]MA[ba]C[Well done - Direct ko for the group, white takes first.RIGHT]) (;W[fa] (;B[cb]C[Black's alive! (Could also play bC18 @ D17 followed by wA19, starting a ko which black takes first and white eeds to win twice to kill!)]) (;B[dc];W[aa];B[ba]MA[aa]C[The alternative..])) (;W[ba];B[cb]C[Black's alive!])) (;W[cb];B[bb]C[Black's alive!]) (;W[fa];B[dc] (;W[bb];B[ab];W[aa];B[ba]MA[aa]C[Too hard a ko for white.]) (;W[cb];B[bb]C[Black's alive!]) (;W[ac];B[ab]C[Black's alive!] (;W[cb];B[bb]C[Black's alive!]) (;W[bb];B[ad]C[Black's alive!]) (;W[ba];B[cb]C[Black's alive!])) (;W[ab];B[ba]C[(bB19 is better than bA17 because after bA17 wB19 bC18 wA16, it's seki...)] (;W[bb];B[ac]C[Black's alive!]) (;W[ac];B[bb]C[Black's alive!])) (;W[ba];B[ab]C[Black's alive!]TR[bb]TR[cb]) (;W[ad];B[ab]C[Black's alive !(bA17 lets white get seki by playing wB19 bC18 wA19)])) (;W[ac];B[ab] (;W[bb];B[ad];W[cb];B[ba];W[aa]MA[ba]C[Too hard a ko for white. (Black got an extra threat - B15!)]) (;W[cb];B[bb]C[Black's alive!]) (;W[fa];B[dc] (;W[cb];B[bb]C[Black's alive!]) (;W[bb];B[ad]C[Black's alive!]) (;W[ba];B[cb]C[Black's alive!])) (;W[ba];B[cb]C[Black's alive!])) (;W[ab];B[ac]C[Seki..]LB[ba:1]LB[cb:2]LB[fa:3]LB[dc:4]LB[ad:5]) (;W[ba];B[ab]C[Black's alive!]TR[cb]TR[bb])) (;W[ac];B[ab] (;W[ca];B[cb] (;W[ea];B[ba];W[ad];B[da]MA[ca]) (;W[ba];B[dc]C[Black's alive!])) (;W[cb];B[bb]C[Black's alive!]) (;W[bb];B[ad]C[Black's alive!]) (;W[ba];B[cb]C[Black's alive!])) (;W[cb];B[bb]C[Black's alive!]) (;W[bb];B[ab]C[Black's alive!]) (;W[ab];B[ac] (;W[ca];B[ea]C[Seki..]LB[ba:1]LB[cb:2]LB[fa:3]LB[dc:4]LB[ad:5]) (;W[cb];B[bb]C[Black's alive!]) (;W[bb];B[cb]C[Black's alive!]) (;W[ba];B[cb]C[Black's alive!])) (;W[ba];B[cb]C[Black's alive!])) (;W[ac];B[ab] (;W[db];B[cb]C[Black's alive!]) (;W[bb];B[ad] (;W[db];B[da]C[Black's alive!]) (;W[cb];B[db]C[Black's alive!]) (;W[ea];B[db]C[Black's alive!]) (;W[da];B[ba]C[Black's alive!]) (;W[ba];B[db]C[Black's alive!]) (;W[ca];B[db]C[Black's alive!])) (;W[cb];B[db]C[Black's alive!]) (;W[ea];B[db]C[Black's alive!]) (;W[da];B[db]C[Black's alive!]) (;W[ca];B[db]C[Black's alive!]) (;W[ba];B[db]C[Black's alive!]) (;W[ad];B[cb]C[Black's alive!])) (;W[bb];B[ab] (;W[ba];B[db]C[Black's alive!]) (;W[db];B[da]C[Black's alive!]) (;W[cb];B[db]C[Black's alive!]) (;W[da];B[db]C[Black's alive!]) (;W[ea];B[db]C[Black's alive!])) (;W[cb];B[db]C[Black's alive!]) (;W[ab];B[ac] (;W[db];B[da]C[Seki...]LB[ca:1]LB[ea:2]LB[ba:3]LB[cb:4]LB[fa:5]LB[dc:6]LB[ad:7] (;W[ca];B[ea]C[Seki..]LB[ba:1]LB[cb:2]LB[fa:3]LB[dc:4]LB[ad:5]) (;W[cb];B[bb]C[Black's alive!]) (;W[bb];B[cb]C[Black's alive!]) (;W[ba];B[cb]C[Black's alive!])) (;W[ea];B[db]C[Black's alive!]) (;W[cb];B[bb]C[Black's alive!]) (;W[da];B[db]C[Black's alive!]) (;W[ca];B[db]C[Black's alive!])) (;W[da];B[ea] (;W[ac];B[db] (;W[bb];B[cb]C[Black's alive!]) (;W[ca];B[ab]C[Black's alive!]) (;W[ba];B[ab]C[Black's alive!]) (;W[ab];B[bb]C[Black's alive!])) (;W[bb];B[cb]C[Black's alive!]) (;W[cb];B[bb]C[Black's alive!]) (;W[db];B[cb]C[Black's alive!]) (;W[ab];B[cb]C[Black's alive!]TR[ac]TR[db]) (;W[ba];B[cb]C[Black's alive!])) (;W[ca];B[db]C[Black's alive!]) (;W[ba];B[db]C[Black's alive!]) (;W[ea];B[db]C[Black's alive!]) (;W[fa];B[ea]C[Black's alive!] (;W[ac];B[ab]C[Black's alive!]) (;W[bb];B[cb]C[Black's alive!]) (;W[cb];B[bb]C[Black's alive!]) (;W[db];B[cb]C[Black's alive!]) (;W[ab];B[ca]C[Black's alive!]) (;W[ca];B[cb]C[Black's alive!]) (;W[ba];B[cb]C[Black's alive!])) (;W[ad];B[ac] (;W[db];B[ea]) (;W[da];B[db]C[Black's alive!]) (;W[ca];B[db]C[Black's alive!]) (;W[cb];B[db]C[Black's alive!]) (;W[ba];B[db]C[Black's alive!]) (;W[bb];B[db]) (;W[ea];B[db]C[Black's alive!])))