(;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[sr]
;B[sq]
;W[qq]
;B[qp]
;W[rp]
;B[ro]
;W[pq]
;B[so]
;W[pp]
;B[qn]
;W[po]
;B[pn]
;W[or]
;B[oq]
;W[nr]
;B[op]
;W[]
;B[oo]
;W[]C[This is the problem position. Black to play.]
(;B[qo]C[This is atari but...]
;W[rq]
(;B[sp]
;W[qs]C[White captures first])
(;B[rs]
;W[sp]C[This allows white an eye and black is lost]))
(;B[sp]
;W[rq]
(;B[qo]
;W[qs]C[Not fast enough])
(;B[rs]
;W[qo]C[White has an eye - black doesn't - white wins]))
(;B[rq]C[Playing into atari is usually daft!]
(;W[sp]C[White has to take the two]
;B[rq]C[And black plays the same point again]
(;W[sq]
;B[qo]
(;W[rq]
;B[rs]C[Eek! White has been run out of liberties!

This is the correct sequence.])
(;W[ps]C[Giving up 4 stones will already be a loss.]
;B[rq]
;W[qq]
;B[pq]
;W[qs]
;B[rs]
;W[ss]
;B[rq]C[This ends with a ko white cannot win.]))
(;W[qo]C[White still can't take the one stone.]
;B[qp]))
(;W[qo]C[White cannot take the one stone...]
;B[qp]C[As he was still in atari!])))
