(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play]
AB[br][cs][hr][bq][hq][hp][ep][cp][co][fo][go][cn][dn][en]
AW[er][gr][dq][cq][gq][fp][dp][do][eo]
C[This is the problem position. Black to play.]
(;B[eq]C[The theme of the problems in BGJ 147 was
adding stones inside the eye shape.

Does adding a second stone here work?]
;W[fs]C[No. White Simply Plays here.]
(;B[fq]
;W[fr]
;B[eq]
;W[ds]
;B[cr]
;W[dr]C[White can get two eyes.])
(;B[dr]
;W[fq]
(;B[ds]
;W[es]
;B[hs]
;W[gs]C[Also two eyes.])
(;B[es]
;W[cr]
;B[bs]
;W[ds]C[Four eyes!]))
(;B[ds]
;W[fq]
;B[es]
;W[gs]C[Still two eyes.]))
(;B[fs]C[As often in Go playing on the oponents's vital
point is the best move. This is correct.]
(;W[fr]
;B[eq]C[Now black plays the inside move.]
(;W[gs]C[Does this make another eye?]
(;B[es]
;W[ds]
;B[dr]C[Black has a clever move here that catches
white short of liberties.]
(;W[cr]C[Snap bakcn shape!]
;B[dr])
(;W[fq]
;B[es]C[Only One eye])
(;W[es]
;B[cr]C[Ouch.]))
(;B[dr]C[If black tries this immediately...]
;W[fq]
;B[es]
;W[cr]C[... the the liberty shortage has gone and white lives,]
;B[bs]
;W[ds]))
(;W[fq]C[If white gains liberties by taking the inside stones...]
;B[gs]C[...Black can just draw back]))
(;W[ds]C[If white tries to make the edge eye...]
;B[gs]
;W[cr]
;B[fq]C[... then black takes the other eye away.])))
