(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[White]PB[Black]AW[ob][jc][qf]AB[nc][pd]LB[ob:A]C[White A is hamete. How should Black respond?]
(;B[nb]CR[nb]
;W[qc]CR[qc]C[O18 is natural]
;B[qd]CR[qd]
;W[rd]CR[rd]
(;B[pc]CR[pc]
;W[rb]CR[rb]
(;B[pb]CR[pb]
;W[qi]CR[qi]C[Black is too concentrated, and White has also taken the corner away from Black. Six stones to capture one stone])
(;B[qb]CR[qb]
;W[rc]CR[rc]
;B[pb]CR[pb]
;W[qi]CR[qi]C[Black is too concentrated, and White has also taken the corner away from Black. Six stones to capture one stone!]))
(;B[re]CR[re]
;W[rc]CR[rc]
;B[qe]CR[qe]
;W[oc]CR[oc]
;B[od]CR[od]
;W[nd]CR[nd]C[White's cut is very serious trouble for black]))
(;B[qe]CR[qe]
;W[pf]CR[pf]
;B[nb]CR[nb]
;W[qc]CR[qc]
;B[pc]CR[pc]
;W[re]CR[re]
;B[pb]CR[pb]
;W[rd]CR[rd]C[Six stones to capture one. And the corner is still up in the air.])
(;B[oc]CR[oc]
(;W[pb]CR[pb]C[CHOICE]
;B[qe]CR[qe]
;W[pf]CR[pf]
;B[nb]CR[nb]
;W[qc]CR[qc]
;B[rd]CR[rd]
;W[rc]CR[rc]
;B[rf]CR[rf]
(;W[ra]CR[ra]C[CHOICE]
;B[qg]CR[qg]C[RIGHT White gets a very small corner and Black has a very strong position on the outside.])
(;W[qh]CR[qh]C[CHOICE]
;B[oa]CR[oa]C[RIGHT The White corner is dead and White's influence on the outside is very small ])
(;W[rg]CR[rg]
;B[oa]CR[oa]C[RIGHT The White corner is dead and White's influence on the outside is very small ]))
(;W[qc]CR[qc]
;B[qd]CR[qd]
;W[rd]CR[rd]
;B[re]CR[re]
;W[rc]CR[rc]
;B[qe]CR[qe]
;W[nb]CR[nb]
;B[pf]CR[pf]C[RIGHT Black has very good strength on the outside])))