(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[White]PB[Black to play and kill]AW[pp][qp][rp][oq][pq][rq][sq][pr][sr]AB[oo][po][qo][ro][mp][op][nq][qq][nr][or][qr][rr]C[White has more liberties than Black, so filling a liberty is no good.]
(;B[ps]
;W[rs]
;B[os]
;W[qs])
(;B[sp]
;W[rs]
;B[ps]
;W[qs])
(;B[ss]
;W[rs]
;B[qs]
;W[ps])
(;B[qs]C[This move threatens to escape or make a dead shape.]
(;W[ps]C[So White should not answer here.]
;B[rs]
;W[ss]
;B[qr])
(;W[rs]C[This is the correct response.]
(;B[ps]
;W[os])
(;B[ss]
;W[ps]
;B[os]C[White is not allowed to connect to make a six shape and anyway a six shape would be alive.
]
;W[rs])))
(;B[rs]C[So this must be the correct move to kill]
(;W[ps]
;B[qs]C[Dead shape.]
;W[ss]
;B[qr])
(;W[ss]
;B[qs]
;W[ps]
;B[qr]C[Still dead shape.])
(;W[qs]
;B[ps]C[Now White is out of liberties]
;W[ss]
;B[sp])))
