(;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[rq]
;W[rs]
;B[sq]
;W[sp]
;B[rp]
;W[so]
;B[pr]
;W[ro]
;B[or]
;W[qo]
;B[os]
;W[qp]
;B[]
;W[oo]
;B[]
;W[oq]
;B[]
;W[nq]
;B[]
;W[nr]C[This is the problem position. Black to play.]
(;B[sr]C[This fails as...]
(;W[qs]C[...white makes a dead shape. Even if black
captures the three stones there is only one
eye as white can play back on the eye point.]
;B[qq]
;W[pq]
;B[ps]
;W[ns]
;B[ss]
;W[rs]C[Dead])
(;W[qq]C[White shouldn't play here as...]
;B[qs]
;W[ss]
;B[rq]
;W[sq]
;B[sr]C[Black plays an under the stones sequence and 
makes two eyes.]))
(;B[qq]C[If black connects on the outside...]
;W[qs]C[white starts to threaten a dead shape]
;B[ss]C[If black plays T2 instead it's just dead]
;W[sr]
;B[ps]
;W[pq]
;B[ss]
;W[rs]
;B[rr]
;W[sr]C[This ends up as ko which is bad for black.])
(;B[ss]
;W[qs]
;B[qq]
(;W[pq]
;B[sr]C[This is just dead.])
(;W[sr]C[If white incorrectly plays here]
;B[ps]
;W[pq]
;B[ss]
;W[rs]
;B[rr]
;W[sr]C[Black salvages a ko.]))
(;B[qs]C[Making the eye must be the right answer.]
;W[qq]C[This is the only thing that whit can try.]
;B[sr]C[Black's trick is to play T2 (T1 clearly fails)]
;W[ss]
;B[rq]C[And when white takes three stones, black
can play the under the stones sequence 
to recapture the three white stones and
make two eyes.

This is the correct sequence.]))
