Problem	15167
Created	2011-08-23
Name	sandbox ko No.2
Source	variation from chinese II -165
Rating

Difficulty	9 dan
Average Solve Time	29 secs
User Attempts	22 / 157
Solve Ratio Rating	2 dan
	rating history

W to win the ko. neither W&B have external ko threat.

(;AB[rr]AB[qq]AB[pp]AB[oq]AB[or]AB[nr]AB[mr]AB[mq]AW[kq]AW[lq]AW[lr]AW[mp]AW[np]AW[nq]AW[op]AW[po]AW[qo]AW[rp]AW[rq]AW[sr]AB[qs]C[neither W&B have external ko threat.]AP[goproblems] (;W[rs]C[];B[ss] (;W[pr];B[ps];W[rs];B[qr]) (;W[pq];B[pr];W[rs] (;B[qr];W[qp];B[ms];W[os];B[ss];W[sq]C[RIGHT])) (;W[qp];B[sq] (;W[pq];B[qr] (;W[pr];B[ps] (;W[pp];B[os] (;W[ms]C[RIGHT]) (;W[sp];B[ms];W[sr]C[RIGHT])) (;W[sp];B[pp] (;W[sr];B[pq]) (;W[pq];B[ms]) (;W[ms];B[pq] (;W[sr];B[ns]) (;W[ns];B[sr]))) (;W[ms];B[pp] (;W[ns];B[pq]) (;W[pq];B[ns]) (;W[sp];B[sr]))) (;W[ms];B[pr]) (;W[sp];B[sr] (;W[pr];B[ps] (;W[pp];B[os];W[ms]C[RIGHT]) (;W[ms];B[pp])) (;W[ms];B[pr]))) (;W[sp];B[pq] (;W[sr];B[ps]) (;W[ps];B[sr]) (;W[ms];B[sr])))) (;W[pr]C[];B[ps]C[White waste local ko threat]) (;W[ms];B[pr]C[White waste local ko threat]) (;W[os];B[rs] (;W[pr];B[ps]C[black is alive]) (;W[ms];B[ns]C[black is alive]) (;W[pq];B[pr]C[black is alive]) (;W[ns];B[ms]C[black is alive])) (;W[ns];B[ms];W[rs];B[qr];W[qp];B[pq]) (;W[ps];B[pr]C[White waste local ko threat.]))