(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play and kill]AW[op][rp][oq][pq][rq][rr][sr]AB[oo][po][qo][ro][np][pp][nq][nr][ns]
(;B[ps]C[This is the killing move.]
;W[qs]C[However seeing the next move is hard.]
;B[rs]
(;W[qr]
;B[sp]C[White is dead.])
(;W[sp]
;B[qr])
(;W[pr]
;B[qr]
;W[qq]
;B[qs])
(;W[ss]C[This is a tricky response.]
;B[pr]C[But black plays here.]
(;W[qr]
;B[sp])
(;W[sp]
;B[qr])))
(;B[pr]C[This is sometimes a good move.]
(;W[or]
;B[ps]C[And in this case white cannot capture the stone
beacuse of self-atari.]
;W[os])
(;W[qr]C[However white can live with the threat of capturing it]
(;B[or]
;W[sp]C[But he may have to give up 3 stones])
(;B[sp]
;W[or]
;B[os]
;W[ps]
;B[qp]
;W[qq]C[This way white lives with 4 points.])
(;B[qs]
(;W[or]C[White shouldn't try to capture in this position.]
;B[os]
;W[rs]
;B[qq]
;W[sp])
(;W[rs]C[White lives easily with this move.]
(;B[sp]
;W[or])
(;B[ps]
;W[sp]))))))
