(;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[dr]
;W[er]
;B[eq]
;W[fr]
;B[dq]
;W[fq]
;B[fp]
;W[gq]
;B[gp]
;W[ep]
;B[dp]
;W[eo]
;B[cq]
;W[do]
;B[hp]
;W[cp]
;B[hq]
;W[co]
;B[hr]
;W[bq]
;B[]
;W[bp]C[This is the problem position. Black to play.]
(;B[ds]C[Black starts with one less liberty than white.
Descending to the edge is a tesuji to gain liberties.
Here it is correct.]
(;W[cs]C[This is usually the tesuji in this shape to keep
balck's liberties down to 2.]
;B[br]
;W[es]C[Despite black being in atari...]
;B[cr]
;W[ar]
;B[bs]
;W[aq]C[White cannot complete the ladder sequence,
because of the corner point being self-atari.]
;B[gr]C[So it is white that gets captured.])
(;W[cr]C[If white tries this one]
;B[br]
;W[bs]
(;B[cs]
;W[ar]
;B[as]
;W[aq]
;B[gr]C[Black has time to fill whites liberties...]
;W[bs]
;B[fs]
;W[cr]
;B[es]C[and captures white.])
(;B[ar]C[Black cannot extend here...]
;W[es]
;B[cs]C[as white sets up the snapback]
;W[cr])))
(;B[br]C[Instead if black tries to make liberties this way...]
;W[ds]
;B[cr]
;W[ar]
;B[gr]
;W[bs]C[White simply wins the capturing race])
(;B[cs]C[This looks fancy but also fails]
;W[br]
;B[es]
;W[cr]
;B[ds]
;W[bs]))
