(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]RU[Japanese]SZ[19]KM[0.00]PW[宋泰坤]PB[金明完]WR[四段]BR[六段]DT[06.05.2003]EV[KAT Cup, 3rd]RO[40]PC[Korea]WT[Cheonbuk]BT[Cheonnam]SO[BiGo Assistant Full Edition]US[BiGo Assistant Full Edition]RE[白胜黑];B[pd];W[dd];B[pq];W[dp];B[fq];W[cn];B[ip];W[qn];B[po];W[rp];B[ro];W[qo];B[qp]LB[pn:A][rn:B][rq:C]C[wich move is better for white ?](;W[rq](;B[rn];W[qm];B[rm];W[ql];B[rl];W[qk];B[rk];W[qj];B[qr];W[qf]C[corner is dead but black is small on the side];B[rj];W[qi];B[nc];W[fc];B[ci];W[ck]LB[bd:C][cd:D][be:B][cf:A]C[Which move is the best for black now ?](;B[bd]LB[cc:A][cd:B][ce:C]C[A is comfortable for black](;W[ce];B[be];W[cg](;B[cf];W[df];B[bf];W[cc];B[cd]C[black can keep this exchange for later (or eventually peep the other side)];W[de];B[ch](;W[lc]LB[qd:A][rd:B][qe:C][re:D]C[white got good thickness and black group is low. Which move is best for black ? ](;B[dr];W[qc];B[qd];W[pc];B[oc];W[rd];B[re](;W[rb];B[sd];W[sc];B[rc];W[dg]LB[op:A][qq:B]C[A is a better Ko treat than B];B[bg];W[rd](;B[ld];W[se];B[kc];W[kq];B[jq];W[kp];B[cq];W[cp];B[bc];W[ic];B[in];W[nq];B[jb]LB[ln:A]C[this is a big move but A is bigger ?];W[dq];B[br]TR[hq]C[how to use black weakness ?](;W[gq];B[fp];W[ho](;B[hp];W[er](;B[eq];W[gp];B[fr];W[fo];B[io];W[bq];B[cr];W[gr]C[black stones are separated. He only has a few points in the corner and a weak group on the center];B[hn];W[go];B[ln];W[nn];B[np];W[op];B[oq];W[oo];B[nr];W[mq];B[mr];W[mp];B[ib];W[lr];B[fm]LB[ik:A]C[maybe this move is too close to white thickness. A would have be less complicated](;W[hl];B[il];W[ik];B[jl];W[hk];B[hm];W[kj];B[dm];W[cm];B[dk];W[dj];B[dl];W[cj]C[important to keep separated];B[bp];W[dn];B[ej];W[fl];B[el];W[bo];B[fi];W[fk];B[ek];W[di];B[hi];W[jk];B[ll];W[cb];B[pp];W[bi];B[bh];W[bj];B[bb];W[ba];B[ah];W[hb];B[pf];W[pg];B[of];W[ih];B[gg];W[if];B[mk];W[mi];B[pn];W[nl];B[nk];W[ol];B[mm];W[ms];B[or];W[nm];B[og];W[km];B[kl];W[kn];B[ni];W[nh];B[mh];W[ab];B[ac];W[lh];B[oh];W[nj];B[ng];W[mj];B[oj];W[ok];B[hg];W[je];B[jh];W[ji];B[kh];W[ig];B[lg];W[lk];B[ml];W[ii];B[he];W[jc];B[li];W[lj];B[hc];W[hd];B[ie];W[hf])(;W[gs]C[white can connect this stones or capture black ones](;B[jr];W[es])(;B[es];W[jr];B[ir];W[is])))(;B[fr];W[ds]C[black is on trouble]))(;B[io]C[if black connects];W[hq]LB[go:B][jr:A]C[connection at A or B are miai]))(;W[hq];B[ir];W[gq];B[fp]C[not good]))(;B[dm]C[is it a Ko treat ?];W[se];B[cm];W[lf]C[this is more interesting for white]))(;W[rc];B[qe];W[pb];B[pf]TR[qi][qj][qk][ql]C[the "wall" bacame a weak group.])(;W[qe];B[rc];W[od]C[idea of giving up the corner for the center];B[pe];W[of];B[oe];W[ne];B[nd];W[pf];B[sd];W[me]C[but corner is too big]))(;B[rd]C[this is the best corner answer (nobi is almost the same)];W[qc];B[qd];W[ob];B[nb];W[oc];B[od];W[rc];B[pc];W[pb];B[rb];W[qb];B[sc]C[white is dead])(;B[re]TR[rj]C[there's no need for white to defend because there is no point on the side. Futhermore white can evade the corner];W[qc]LB[pb:B][pc:A]C[A or B are also possible];B[pc];W[pb];B[ob];W[rd];B[qe];W[rb];B[pa];W[qa]C[there's a Ko fight]))(;W[dg];B[bg]LB[eg:B][fg:C][eh:A]C[why this exchange is not good for white ? because A, B or C are also sente for white. And it can helps him building something bigger];W[bc]C[white can get this sente anytime]))(;B[cc];W[bf];B[eb]C[black live small in the corner and white is strong outside]))(;W[cd];B[be];W[bc];B[bb];W[cc];B[cf]C[black shape is still good]))(;B[be];W[bd](;B[ce];W[cd]C[this way, white has a to big corner])(;B[cd](;W[cc];B[ce];W[bc];B[de];W[ed]C[this way, corner is smaller and black is stronger])(;W[ce]C[if white ataris the other side];B[cc];W[bc];B[de];W[cf];B[dc];W[ed](;B[bf];W[bb];B[cg];W[df];B[eg];W[ef];B[ff]C[this is joseki];W[dg];B[dh];W[ee];B[bh]C[but white has a huge corner and he is Sente])(;B[bb];W[bf];B[ac];W[ae];B[ca]C[black is small on the corner and ...];W[db];B[eb];W[ec];B[cb];W[fb];B[ea]C[now white is very strong outside])))(;B[ed]C[we should check this move](;W[ec];B[cd];W[cc];B[ce];W[bc];B[de]C[even better for black, but how to punish it ?])(;W[ee];B[cd];W[cc];B[ce];W[bc](;B[dc];W[de];B[ec];W[fd];B[fb];W[ea];B[cb];W[da];B[eb];W[gb];B[fa];W[ga];B[db];W[bb];B[ca];W[ba]C[black is dead])(;B[de]C[if black ataris the other side, he give up too much points];W[dc];B[ef];W[fe]))))(;B[cd]LB[cc:A][ce:B](;W[cc];B[ce];W[bc];B[de];W[ed])(;W[ce](;B[be];W[bd];B[cc];W[bc];B[de];W[cf]C[same as before])(;B[dc](;W[ed];B[bc];W[be];B[eb];W[fb];B[cb];W[ei]C[very good thickness for white])(;W[cc](;B[ed];W[de];B[ec];W[cb]TR[ci]C[marked stone became very weak])(;B[bd];W[be](;B[ed];W[de];B[ec];W[cb]C[better for white])(;B[de];W[ed];B[bc];W[cb];B[bb];W[db];B[cf]C[can black win the semiai ?];W[bf];B[cg];W[bg];B[bh];W[df];B[ee];W[dg];B[ch];W[fe];B[ef];W[eg]C[ladder is good for black])))))))(;B[qm]LB[pn:A][rn:B]C[Kanda Eio vs Fujisawa Rina, 2010. Black fighting mve Where should white play ? A or B ?](;W[pn];B[rn];W[pm];B[ql];W[oo];B[nq];W[np];B[oq];W[lp];B[mq];W[ln];B[lq];W[pl];B[qk];W[oj]C[there's a Ko in the bottom right corner];AE[pd]AB[qd];B[oc];W[rd];B[qe];W[qc];B[pc];W[qb];B[re];W[sc]LB[ob:B][pb:A]C[white is alive. But the exchange A-B is not good for white](;B[];W[qq]C[white did not played this because it was too small at this stage and if he wants to play a Ko, his center group would suffer.];B[pp];W[pr];B[or];W[qs];B[sr];W[rr];B[os];W[ps];B[rs]C[Ko])(;B[ra];W[rb];B[se];W[sa];B[sd];W[rc];B[sb](;W[qa]C[white is alive])(;W[pb];B[ob]C[but after this exchange, there's a Ko])))(;W[rn]C[this should be best move after the C choice made at the beginning];B[pn];W[pm];B[rm];W[so];B[qk];W[om];B[no];W[ok];B[pi];W[ll]C[this is the best for both side])))(;W[rn]C[B is the best local move];B[rq];W[so](;B[qk]C[if black pincer at third line];W[rl]C[white is alive])(;B[pk]C[if black pincer at the fourth line](;W[rk]C[white make is base of life];B[pn]C[but black can connect his stones. White is small and black has built a big moyo])(;W[om]C[if white tries to escape this side];B[oo](;W[mm]C[how can black separte white stones ?];B[pm];W[pn];B[on];W[pl];B[ol]TR[nm]C[marked space seems also interesting but with this move, there's a Ko and white can't win it];W[qm];B[nm];W[nl];B[pm];W[qq];B[ql];W[pp];B[op]C[better for black !];W[qp];B[jd])(;W[pm]C[if white wants to prevent the cut];B[rl]C[but white only has one eye])(;W[ql];B[qk];W[rl];B[qf]C[this should be the best for both players]))))(;W[pn];B[rn];W[oo];B[pp];W[ql];B[rq];W[nm]C[this is joseki : black has a big corner but white influence]))