Problem	13737
Created	2010-05-29
Source	Chinese book
Rating

Difficulty	1.2 dan
Average Solve Time	63 secs
User Attempts	256 / 850
Solve Ratio Rating	4 kyu
	rating history

I thought this problem was pretty cool. Hope I didn't mess up any solutions XD

(;AW[bq]AW[bp]AW[dq]AW[cq]AB[eq]AB[dp]AB[fr]AB[fp]AB[gp]AB[go]AB[hq]AB[hr]AB[gs]AW[ir]AW[iq]AW[hp]AW[ho]AW[eo]AW[gn]AW[fo]AW[hn]AW[is]AW[hs]AW[es]AB[dr]AW[do]AW[co]C[White to kill unconditionally]AP[goproblems] (;W[gq];B[gr] (;W[ep];B[fq] (;W[ds];B[cr] (;W[cs];B[br] (;W[bs];B[ar];W[er]C[RIGHT]) (;W[ar];B[bs])) (;W[br];B[cs])) (;W[cr];B[ds]) (;W[cs];B[ds]) (;W[er];B[ds])) (;W[ds];B[cr] (;W[ep];B[fq] (;W[cs];B[br] (;W[bs];B[ar];W[er]C[RIGHT]) (;W[ar];B[bs])) (;W[br];B[cs])) (;W[cs];B[br] (;W[ep] (;B[fq] (;W[bs];B[ar];W[er]C[RIGHT]) (;W[ar];B[bs])) (;B[ar] (;W[er];B[fq];W[bs]C[RIGHT]) (;W[bs];B[er])) (;B[er] (;W[ar];B[fq];W[bs]C[RIGHT]) (;W[fq];B[ar]) (;W[bs];B[ar]))) (;W[bs];B[er] (;W[ep];B[ar]C[Seki]) (;W[ar];B[fs];W[ep];B[as] (;W[bs];B[fq]) (;W[fq];B[aq])))) (;W[br];B[cs])) (;W[er];B[ds])) (;W[fs];B[gr]) (;W[gr];B[gq]) (;W[er];B[ds]) (;W[ds];B[gq] (;W[fs];B[er]C[Ko. Yes, white can extend twice but still ko is not optimal.]) (;W[er];B[fs];W[cr];B[ep]) (;W[ep];B[er]) (;W[cr];B[fs]) (;W[cs];B[fs])))