Problem	2026
Created	2003-03-21
Source
Rating

Difficulty	8 dan
Average Solve Time	58 secs
User Attempts	201 / 2469
Solve Ratio Rating	4 dan
	rating history

White and Black both have three liberties, so whoever moves first should win, right? It's not that simple. What's the tesuji? (Ko is not sufficient)

(;AB[dc]AB[ec]AB[fc]AB[gd]AB[hd]AB[fe]AB[ff]AB[ef]AB[cd]AB[bd]AB[be]AB[bf]AB[bg]AB[bh]AB[bi]AW[cc]AW[bc]AW[dd]AW[ed]AW[fd]AW[ee]AW[de]AW[ce]AW[cf]AW[cg]AW[ch]AW[ci]AW[gc]AW[gb]AW[ge]AW[ib]C[Black to save the marked stones.]TR[dc]TR[ec]TR[fc] (;B[db] (;W[cb]C[CHOICE] (;B[ba];W[ca] (;B[da];W[ab];B[ad];W[fb];B[ac]C[RIGHT]) (;B[ac];W[ab] (;B[da];W[ad];B[ae];W[fb] (;B[ac]C[only ko]) (;B[bb];W[aa] (;B[ac];W[ea]) (;B[bb];W[ea]))) (;B[ad];W[da] (;B[ea]C[RIGHT]) (;B[bb];W[ea]) (;B[fb];W[fa])))) (;B[da] (;W[ba];B[ab];W[ac] (;B[ca];W[fb] (;B[ad]C[CHOICERIGHT]) (;B[aa];W[bb]) (;B[bb];W[aa] (;B[ad];W[ea]) (;B[bb];W[ea];B[ab]C[RIGHT]))) (;B[ad];W[fb] (;B[ca]C[RIGHT]) (;B[bb];W[aa] (;B[bb];W[ea]) (;B[ca];W[ea]))) (;B[bb];W[fb] (;B[ca];W[aa] (;B[bb]C[RIGHT];W[ea];B[ab]C[RIGHT]) (;B[ab]C[RIGHT]) (;B[ad];W[ea])) (;B[ad];W[aa] (;B[bb];W[ea]) (;B[ca];W[ea]))) (;B[aa];W[fb] (;B[ad];W[ea]) (;B[ca];W[bb]))) (;W[ab];B[ba];W[ca];B[ad];W[fb];B[ac]C[CHOICERIGHT])) (;B[ac];W[ba] (;B[ab];W[da] (;B[bb];W[fb];B[ca]C[Black has connected, but not in the most profitable way.RIGHT]) (;B[ea];W[fb];B[ca]C[only ko])) (;B[da];W[ab])) (;B[ca];W[ba] (;B[da];W[ab]C[White lives]) (;B[ac];W[da];B[ea];W[ca] (;B[ab];W[fb]) (;B[aa];W[ab]) (;B[fb];W[ga] (;B[aa];W[ab]) (;B[ab];W[fa])))) (;B[ab];W[fb])) (;W[bb]C[CHOICE] (;B[ac];W[ba] (;B[ca];W[fb] (;B[ab];W[eb];B[ad]C[RIGHT]) (;B[ad];W[cb])) (;B[cb];W[fb];B[ab];W[eb]) (;B[ab];W[da] (;B[ad];W[fb]) (;B[ea];W[cb] (;B[fb];W[ga];B[ad];W[fa];B[ca]C[ko]) (;B[ad];W[fb] (;B[ca]C[ko]) (;B[eb];W[fa])) (;B[ca]C[ko])) (;B[ca];W[cb];B[ea];W[fb]C[ko]) (;B[cb];W[fb]) (;B[eb];W[ea] (;B[fa];W[ca]) (;B[fb];W[fa]) (;B[cb];W[ca]) (;B[ad];W[fb])) (;B[fb];W[fa]C[Ko with E19 is all that remains for black.]))) (;B[cb];W[ba] (;B[ac];W[fb];B[ab];W[eb]) (;B[ca];W[fb])) (;B[ca];W[ba] (;B[ac]C[RIGHT];W[fb] (;B[ab];W[eb];B[ad]C[RIGHT]) (;B[ad];W[cb])) (;B[ad];W[fb];B[ac];W[cb]) (;B[ab];W[ac] (;B[ad];W[fb];B[cb]C[RIGHT]) (;B[cb];W[fb];B[ad]C[RIGHT])) (;B[aa];W[fb] (;B[ac];W[ab] (;B[ad];W[eb]) (;B[cb];W[ad];B[ae];W[eb])) (;B[ab];W[ac]) (;B[cb];W[eb])) (;B[cb];W[fb])) (;B[ba];W[ca] (;B[cb];W[aa];B[da];W[fb] (;B[ba]C[only ko]) (;B[ac];W[ea]C[ko];B[ba]C[ko])) (;B[da];W[aa] (;B[ac];W[fb] (;B[cb];W[ea];B[ba]C[ko]) (;B[ad];W[ea];B[ab];W[eb])) (;B[cb];W[fb] (;B[ac];W[ea];B[ba]C[ko]) (;B[ba]C[ko]))) (;B[ac];W[da] (;B[ea];W[aa] (;B[cb];W[fb];B[ba];W[ca] (;B[ad];W[eb];B[ab];W[da]) (;B[da];W[fa]C[ko])) (;B[ad];W[fa])) (;B[cb];W[aa] (;B[ea];W[fb];B[ba];W[ca] (;B[da];W[fa]C[ko]) (;B[ad];W[eb];B[ab];W[da])) (;B[ad];W[fb])) (;B[ab];W[aa];B[ad];W[fb]C[ko]))))) (;B[bb];W[cb] (;B[db];W[ab] (;B[ba];W[ca] (;B[ad];W[fb] (;B[ac];W[aa];B[bb];W[da]) (;B[da];W[aa];B[ac];W[ea])) (;B[da];W[aa] (;B[ad];W[fb] (;B[ac];W[ea]) (;B[bb];W[ea])) (;B[bb];W[fb];B[ad];W[ea]))) (;B[ca];W[ba]C[White has two eyes.])) (;B[ac];W[db]) (;B[ca];W[db])) (;B[cb];W[bb] (;B[db];W[ba];B[ac];W[fb] (;B[ab];W[eb]) (;B[ca];W[eb])) (;B[ba];W[db] (;B[da];W[ca]C[Ko]) (;B[ac];W[ca];B[ab];W[aa]C[Ko])) (;B[ac];W[db]) (;B[ca];W[db];B[eb];W[ea];B[da];W[fa]) (;B[da];W[ba] (;B[ac];W[fb];B[eb];W[fa] (;B[ab];W[ea]) (;B[ea];W[ca])) (;B[eb];W[fa];B[ac];W[ea]) (;B[fb];W[fa] (;B[ac];W[eb];B[db];W[ca]) (;B[ea];W[ga] (;B[ca];W[db]) (;B[db];W[ca]) (;B[ac];W[db];B[eb];W[ca]))))) (;B[ac];W[db] (;B[bb];W[cb]) (;B[cb];W[bb]) (;B[eb];W[ea])) (;B[ca];W[db]) (;B[da];W[db] (;B[cb];W[eb]) (;B[eb];W[cb] (;B[ac];W[fb]) (;B[ea];W[fa];B[ca];W[ba]))) (;B[fb];W[db]))