Problem	8490
Created	2006-05-02
Name	k15
Source	dashnet
Rating

Difficulty	7 dan
Average Solve Time	58 secs
User Attempts	138 / 958
Solve Ratio Rating	2 dan
	rating history

Ko is not a solution

(;AB[bq]AB[cq]AB[dr]AB[er]AB[fq]AB[gp]AB[fo]AB[en]AB[dm]AB[cl]AB[cn]AW[cr]AW[br]AW[dq]AW[dp]AW[cp]C[Black to kill]AP[goproblems] (;B[cs] (;W[bs]C[CHOICE] (;B[ar];W[ds] (;B[bo];W[bp];B[ap]C[CHOICERIGHT]) (;B[ap];W[bo])) (;B[aq];W[bp];B[ar];W[ds]) (;B[bp];W[bo];B[ar];W[ds] (;B[aq];W[ao]) (;B[co];W[ap])) (;B[bo];W[bp])) (;W[aq];B[bs];W[bp];B[bo]C[RIGHT]) (;W[ar];B[bs];W[bo];B[bn]C[RIGHT]) (;W[bp];B[bs] (;W[bn];B[bm];W[aq];B[bo]C[RIGHT]) (;W[aq]))) (;B[bp];W[bo] (;B[cs];W[aq] (;B[bs];W[ap]LB[bn:a]LB[bq:b]C[either a or b - w lives]) (;B[ap];W[ao]) (;B[bn];W[ap]) (;B[as];W[ap])) (;B[bs];W[aq]) (;B[bn];W[aq]) (;B[aq];W[ar]) (;B[ao];W[aq]) (;B[ap];W[ao]) (;B[ar];W[ap]) (;B[co];W[ap])) (;B[bo];W[bp] (;B[cs];W[bs]) (;B[aq];W[ap];B[cs];W[ar])) (;B[aq];W[ar]C[] (;B[cs];W[bp];B[bs];W[ap];B[bq];W[bn]) (;B[bo];W[bp];B[cs];W[ap];B[bq];W[bs]) (;B[ao];W[ap])) (;B[ap];W[bp] (;B[cs];W[aq];B[bs];W[bo]) (;B[ar];W[ao])) (;B[bs];W[cs] (;B[ar];W[as]C[ko]) (;B[ds];W[as]) (;B[bp];W[bo] (;B[ar];W[as]C[ko]) (;B[ds];W[ar])) (;B[aq];W[bp];B[ar];W[as]C[ko])) (;B[ar];W[bp]))