(;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[or]
;W[pr]
;B[oq]
;W[pq]
;B[op]
;W[qr]
;B[pp]
;W[qp]
;B[qo]
;W[rp]
;B[ro]
;W[rq]
;B[so]
;W[po]
;B[sq]
;W[qn]
;B[rn]
;W[pn]
;B[]
;W[rm]
;B[]
;W[qm]C[This is the problem position. Black to play.]
(;B[sp]
;W[sr]C[This simply fails as this is atari.])
(;B[sr]
;W[sp]C[This is atari too - any plays on the first line also clearly fail.])
(;B[rr]C[This must be the vital spot.]
(;W[sp]C[White cannot try this as it's self-atari.])
(;W[rs]
;B[sr]C[White still fails with T4 so]
(;W[qq]
;B[sp]
;W[sm]
;B[ps]C[As white needs two moves to play either T1 or T6
he runs out of liberties.

This is the correct sequence.])
(;W[qs]
;B[sp]
;W[qq]
;B[os]C[This also fails.]))
(;W[sr]
;B[ss]
;W[qs]
;B[sp]
;W[qq]
;B[os]C[The throw in line doesn't work for white either.])))
