Problem	17561
Created	2013-12-21
Source	KGS: Munisai (3k) vs. Nire (5k)
Rating

Difficulty	10 kyu
Average Solve Time	82 secs
User Attempts	406 / 1219
Solve Ratio Rating	5 kyu
	rating history

(;AB[nc]AB[ob]AB[nb]AB[mc]AB[lc]AB[kb]AB[jc]AB[ib]AB[ja]AW[hb]AW[hc]AW[ic]AW[kc]AW[jd]AW[kd]AW[ld]AW[md]AW[nd]AW[oc]AW[pb]AW[pc]C[Black has the next move. Assuming this is the biggest location remaining on the board, can Black's group live, is it dead, or is there a ko?FORCE]LB[lf:Dead]LB[nf:Ko]LB[jf:Live]AP[goproblems] (;W[jf];B[jg]AW[ib]AW[ja]AW[jc]AW[kb]AW[lc]AW[mc]AW[nc]AW[nb]AW[ob]AB[pb]AB[pc]AB[oc]AB[nd]AB[md]AB[ld]AB[kd]AB[jd]AB[ic]AB[hc]AB[hb]C[Defend.]AB[jg]AB[kc] (;W[la]C[] (;B[mb] (;W[ma] (;B[oa];W[jb]C[RIGHT]) (;B[jb];W[oa]C[RIGHT])) (;W[oa] (;B[jb] (;W[ma]) (;W[ka];B[ma])) (;B[ma];W[jb]C[RIGHT])) (;W[jb]C[RIGHT]) (;W[na];B[jb]C[Ko.])) (;B[oa] (;W[na] (;B[mb];W[jb]C[RIGHT]) (;B[jb] (;W[mb]C[RIGHT]) (;W[ia];B[mb];W[jc]C[Ko.]))) (;W[mb] (;B[jb] (;W[na]) (;W[ia];B[na];W[jc]C[Ko.])) (;B[na] (;W[jb]C[RIGHT]) (;W[ma];B[jb];W[pa];B[oa];W[jc]C[Ko.]))) (;W[ma];B[jb]C[Ko.]) (;W[jb]C[RIGHT]))) (;W[jb];B[la]C[] (;W[ma];B[lb];W[oa];B[pa]) (;W[oa];B[ma]) (;W[lb];B[ma])) (;W[ma] (;B[jb] (;W[lb]C[RIGHT]) (;W[oa]C[RIGHT]) (;W[ia];B[oa] (;W[lb];B[ka]C[Ko.]) (;W[la];B[jc])) (;W[ka]C[RIGHT]) (;W[mb];B[oa]) (;W[la];B[oa]C[Ko.])) (;B[lb] (;W[la] (;B[oa];W[jb]C[RIGHT]) (;B[jb];W[oa];B[ia];W[ka]C[RIGHT])) (;W[oa] (;B[jb];W[ka];B[ia];W[la]C[RIGHT]) (;B[la] (;W[mb]C[RIGHT]) (;W[jb];B[pa]) (;W[ka]C[RIGHT])))) (;B[oa] (;W[jb]C[RIGHT]) (;W[lb]C[RIGHT]))) (;W[oa];B[la] (;W[ma];B[lb] (;W[mb]C[RIGHT]) (;W[jb]) (;W[ka]C[RIGHT])) (;W[lb];B[ma]) (;W[mb];B[ma]) (;W[jb];B[ma])) (;W[na];B[la]) (;W[lb];B[ma] (;W[oa];B[la]) (;W[la];B[jb]C[Ko.]) (;W[jb];B[la])) (;W[mb];B[la] (;W[ma];B[oa]) (;W[oa];B[ma]))) (;W[lf];B[la]C[White to kill. Ko is not good enough.] (;W[oa];B[na] (;W[mb];B[jb]) (;W[jb];B[mb];W[ia];B[ka])) (;W[ma];B[jb] (;W[oa];B[na]) (;W[mb];B[lg]C[Black plays elsewhere.];W[oa];B[lb]) (;W[na];B[oa])) (;W[jb];B[mb] (;W[oa];B[na];W[ia];B[ka]) (;W[ia];B[ka];W[oa];B[na]) (;W[ma];B[na];W[ia];B[ka])) (;W[mb];B[oa] (;W[jb];B[ma];W[ia];B[ka]) (;W[ma];B[jb])) (;W[na];B[oa])) (;W[nf];B[la]C[White to play to find the ko.] (;W[oa];B[na] (;W[jb];B[mb];W[ia];B[ka]) (;W[mb];B[jb])) (;W[ma];B[jb] (;W[oa];B[na]) (;W[na];B[oa]) (;W[mb];B[ng]C[Black plays elsewhere.];W[oa];B[lb])) (;W[jb];B[mb] (;W[oa];B[na];W[ia];B[ka]) (;W[ia];B[ka];W[oa];B[na]) (;W[ma];B[na];W[ia];B[ka])) (;W[mb];B[oa] (;W[jb];B[ma];W[ia];B[ka]) (;W[ma];B[jb])) (;W[na];B[oa])))