(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play]C[Just play through the moves to move 22 which is the problem position. These do not represent a game sequence!]
;B[qr]
;W[rr]
;B[pr]
;W[qq]
;B[or]
;W[pq]
;B[nq]
;W[oq]
;B[np]
;W[nr]
;B[op]
;W[mr]
;B[pp]
;W[qp]
;B[qo]
;W[rp]
;B[ro]
;W[sp]
;B[so]
;W[lq]
;B[]
;W[jq]C[This is the problem position. Black to play.]
(;B[sq]C[This black move is atari....]
;W[rq]
;B[rs]
;W[sr]
;B[qs]
;W[os]C[... but when white makes an eye the black stones are
short of liberties and he can never approach white
without be captured himself. So incorrect.])
(;B[rs]
;W[sr]
;B[sq]
;W[rq]
;B[qs]
;W[os]C[Again this sequence fails as white makes the eye.])
(;B[sr]C[Correct. This black move thratens the snap back move or leave white short of liberties.]
(;W[rs]
;B[rq]
;W[sq]
;B[rq]C[The snap back])
(;W[rq]
;B[rs]C[White is in atari - no escape!])
(;W[ss]
;B[rs]
;W[sq]C[This is not a ko!])))
