goproblems.com Problem

Problem	8760
Created	2006-06-21
Source	Sensei's Library
Rating

Difficulty	4.8 kyu
Average Solve Time	45 secs
User Attempts	992 / 3200
Solve Ratio Rating	4 kyu
	rating history

Tripod groups aren't always alive.

(;AB[cb]AB[cc]AB[bd]AW[cd]AW[dc]AW[ec]AW[fb]AW[ce]C[White to kill.]AW[cg]AW[gc]AP[goproblems] (;W[be];B[ac] (;W[bb];B[ba] (;W[ab];B[db] (;W[da];B[eb] (;W[ea]C[The presence of the marked stone had sealed black's fate. RIGHT]TR[fb]) (;W[ca];B[ea]) (;W[ae];B[ea];W[ad];B[bc])) (;W[eb];B[da])) (;W[bc];B[ab]) (;W[db];B[ab]) (;W[ae];B[ab];W[ad];B[bc])) (;W[db];B[bb]) (;W[ba];B[bb];W[ca];B[db] (;W[eb];B[da]) (;W[da];B[ea];W[eb];B[aa])) (;W[ae] (;B[ba] (;W[ad];B[db];W[bc];B[ab];W[da];B[ea];W[eb]C[RIGHT]) (;W[db];B[ad];W[ab]C[RIGHT])) (;B[bb];W[ad];B[aa];W[ca];B[db];W[da];B[ea];W[eb]C[RIGHT]))) (;W[db];B[bb]C[Black is alive, see problem 4798.]) (;W[ac]C[Black is alive. See naviagte solution for how the exchange would take place.];B[ab];W[bb];B[ba];W[aa];B[bc];W[ca];B[db];W[eb];B[da];W[be];B[ad]C[Life in a double ko.]) (;W[ba];B[bb]C[CHOICE] (;W[ac];B[be] (;W[ca];B[db];W[da];B[ea] (;W[eb];B[aa]) (;W[bf])) (;W[bf];B[ab] (;W[ae];B[bc];W[ca];B[db];W[da];B[ea];W[eb];B[aa]) (;W[db];B[ca])) (;W[ab];B[bf] (;W[bc];B[ad] (;W[af];B[ca]) (;W[db];B[aa];W[ab];B[ca] (;W[da];B[bc];W[af];B[ac]) (;W[ac];B[bc]) (;W[aa];B[ac]))) (;W[bg];B[af] (;W[bc];B[ad];W[ca];B[db];W[da];B[aa] (;W[ea];B[ab]) (;W[ab];B[ea])) (;W[ad];B[db])))) (;W[be];B[ac];W[ca];B[db] (;W[eb];B[da]) (;W[da];B[ea];W[eb];B[aa])) (;W[ab];B[ac];W[ca];B[be]) (;W[ca];B[ac];W[be];B[db] (;W[eb];B[da]) (;W[da];B[ea];W[eb];B[aa])) (;W[db];B[ac] (;W[be];B[ca]) (;W[ca];B[be] (;W[bf];B[ae]) (;W[ae];B[bf])))) (;W[bc];B[bb];W[ac];B[ad];W[ca];B[ba] (;W[ab];B[db];W[da];B[eb];W[ea];B[fa];W[ea];B[da]) (;W[db];B[ab])) (;W[ad];B[ac];W[be];B[ae];W[bb];B[db];W[eb];B[ba];W[da];B[ab]) (;W[ab];B[be] (;W[bf];B[ac];W[ae];B[bb];W[af];B[aa];W[ad];B[ca];W[bc];B[bd]) (;W[bc];B[bb])) (;W[bb];B[ab] (;W[ba];B[bc];W[be];B[ad]) (;W[ca];B[bc]) (;W[ac];B[ba];W[aa];B[bc];W[ca];B[db];W[eb];B[da];W[be];B[ad]C[Life in a double ko.])))