(;GM[1]FF[3] RU[Japanese]SZ[19]HA[0]KM[5.5] PW[White] PB[Black] GN[White (W) vs. Black (B)] DT[1999-07-28] SY[Cgoban 1.9.2]TM[30:00(5x1:00)];AW[pm][po][op]AB[on][lp][qp] LB[qp:1][op:2][lp:3][pm:4][on:5][po:6] C[how to continue after 6 for black? ] (;B[pn];W[qo] (;B[qn];W[rn] (;B[qm]C[ ];W[rp] C[RIGHT white gets the corner, black gets outside thickness ]) (;B[rm];W[ro];B[qm]LB[rm:A][rn:1] C[now A looks bad: if white were to play at 1 with no A, black would not block ]) (;B[ro];W[rp]) (;B[rp];W[ro];B[qm]C[RIGHT ]) ) (;B[ro];W[rn];B[rp];W[qn]) (;B[oo];W[qn];B[pp];W[oq]) (;B[pp];W[oo]C[this exchange just helps white ]) ) (;B[qo];W[pn]LB[on:A]C[what's black A doing now? ]) (;B[qn];W[pn]C[yuck ]) (;B[np];W[oq]C[this exchange doesn't really help black ]) (;B[pp];W[oo]TR[on]LB[qp:A] C[this exchange weakens the marked stone and makes white stronger outside. joseki sacrifices A ]) (;B[pq];W[oq] (;B[qo];W[pn]LB[on:A]C[what's A doing? corner still weak too ]) (;B[pn];W[qo] (;B[qn];W[rn]LB[pq:A][oq:B]C[now the A-B exchange looks really bad ]) (;B[ro];W[qn]) ) ) (;B[oq];W[nq];B[pq];W[mp] (;B[qo];W[pn]LB[lp:A]C[A looks bad ]) (;B[pn];W[qo];B[qn];W[ro]) ) )