invalid problem set
Problem | 4708 |
Created | 2004-06-27 |
Source | GZP middle 189 |
Rating | |
Difficulty | 7 dan |
Average Solve Time | 73 secs |
User Attempts |
156 / 1514 |
Solve Ratio Rating | 3 dan |
| rating history |
(;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!])))
Toggle next/previous buttons