(;B[qd]SZ[19]DT[1842-05-16]PC[house of Mr Isoda]PB[Honinbo Shuwa]PW[Inoue Genan Inseki]WR[8dan]RE[B+6]US[tasuki];W[oc]C[ White plays 2 to immediately challenge Black, usually to avoid a normal pattern of fuseki.];B[ec]C[ Black 3 is, in its way, a kind of standard reply to White 2. It aims to play at A next. Because of this, it usually prevents White from playing at B.];W[pf]C[ White 4 was often used by Genan.];B[od];W[nd]
;B[oe];W[pc];B[qe];W[qc];B[qi];W[de];B[cd];W[ce];B[bd];W[mf];B[of];W[gc]C[ White is attempting to make a moyo on the upper side.];B[fc]
;W[gd];B[ee];W[do]C[ White 22 is treating the two White stones in the upper corner lightly, but White will rescue them, depending on how Black plays.];B[cj];W[di]C[ White 24 is natural to prevent a Black moyo appearing here.];B[ci];W[dh];B[cm]C[ Black 27 makes a base for his stones.];W[fe]C[ White 28 starts some hand to hand fighting.];B[ef];W[ff]
;B[eg];W[fg];B[eh];W[fh];B[ei];W[dj];B[dk];W[ej];B[fi];W[dl];B[ek];W[fj];B[gi]
;W[dd];B[dc];W[ck];B[el];W[bk];B[ch];W[cg];B[dg];W[fl];B[fk];W[gj];B[bg];W[cf]
;B[ed];W[dm];B[em];W[dn];B[gl];W[hj];B[hi];W[ij];B[il]C[ The moves from Black 53 to 65 are all indispensible.];W[jf];B[jh];W[kj]C[ White plays 66 to encircle territory and to prompt Black 67, which induces White 68. This is the correct order of moves.]
;B[gn]C[ Black 69 is necessary to secure his group.];W[oi];B[hg];W[qj];B[rj];W[qh];B[pj];W[pi];B[qk];W[ri];B[ie];W[if];B[hf]
;W[jd];B[hd];W[hc];B[me];W[lf];B[ne];W[md];B[le];W[kd];B[kf];W[kg];B[ke];W[je]
;B[jg];W[kh];B[rc];W[rb];B[rh]C[ Once this ko starts, neither player can give an inch.];W[qj];B[ld];W[lc];B[qi];W[bh];B[bi];W[qj];B[mc]
;W[nc];B[qi];W[bf];B[ah];W[qj];B[kc];W[mb];B[qi];W[af];B[cl];W[bm];B[ki];W[qj]
;B[lb];W[mc];B[qi];W[ag]C[ Ignoring the ko for the moment, White tries to revive his lost group.];B[lj];W[qj];B[ic];W[jc];B[qi];W[li];B[ji];W[qj];B[ib]
;W[id];B[qi];W[mj];B[lk];W[qj];B[he];W[jb];B[qi];W[mh];B[si];W[oj];B[ok];W[mk]
;B[pq];W[jj];B[ll];W[ol];B[eq];W[cq];B[mp];W[bh];B[gp];W[nk]C[ White 56 is a thick move.];B[mn]C[ White was confident that he could allow Black to surround a large territory and still win.];W[gq]C[ White 58 probes Black reply.]
;B[fq];W[hp];B[hq];W[mq];B[nq];W[lp];B[gr];W[nr];B[np];W[kq]C[ White 60 to 68 are excellent moves. White will welcome a ko fight since he has a lot of threats.];B[or];W[lr];B[jr]
;W[ln];B[lm];W[jq];B[pk];W[nm];B[lo];W[ko];B[kn];W[jo]C[ When White lives with White 80 the game is very close, either jigo or a 1 point difference.];B[ns];W[mr];B[pm];W[on]
;B[pn];W[bc];B[cc];W[ai];B[ir]C[ Playing 88 allows Black to play the moves on the lower edge, but he still has a lo in the upper left corner.];W[kr];B[cr];W[ad];B[bb];W[br];B[dr];W[ab];B[ac]
;W[oo]C[ White 98 is to provide ko threats.];B[pl]C[ Genan may have been surprised at Black 99 which prevents a White invasion in the corner and threatens to cut by playing A, White B, Black C.];W[bc];B[ca];W[qg];B[og];W[ph];B[rg];W[fb];B[ac];W[op];B[oq]
;W[bc];B[eb];W[nn]C[ This is the best connection.];B[gb];W[hb];B[fa];W[rd];B[re];W[sc];B[cp];W[bp];B[dp];W[co]
;B[ip];W[jp];B[in];W[fo];B[fn];W[eo];B[ho];W[ac];B[kk];W[qf];B[rf];W[jn];B[jm]

(;W[ps]C[ If White plays at "a".. White therefore attempts to gain another point or even to live inside Black's corner.]
(;B[os]C[ If Black plays at "a".. Black does not concede an inch!];W[qo]C[ White has to come into the corner and try to live.];B[po];W[qq];B[pp];W[qr]C[ How should Black kill the corner? There are moves at A, B, C and D.]
(;B[rn]C[ If Black plays at "a", it looks like a ko. If he plays "b" or "c", White will live easily. Black 43 is the only move.];W[ro];B[so];W[cs];B[ds];W[bs];B[se];W[jk];B[jl];W[gk];B[hk];W[en];B[fm]
;W[no];B[mo];W[js];B[is];W[ks];B[sd];W[rc];B[ms];W[ba];B[aa];W[sp]
(;B[qp]
(;W[ba]C[ If White tries to live with "a"..];B[cb];W[ae])
(;W[rp];B[sr];W[rr];B[sq];W[ss]
(;B[rs]C[   Black 6 would be a mistake. "a" is better.];W[qs];B[ss];W[rq];B[sr];W[ss]C[   White will be able to live in ko.])
(;B[qs]C[     White 1 is the tesuji. This forces White to fill in one of his own     liberties.];W[pr];B[rs];W[ss];B[rs]
(;W[rq];B[sn]C[     White cannot atari at A and dies.];W[ss];B[sr])
(;W[sn];B[qn]C[       Black 2 keeps White down to one liberty and prevents White playing       atari at A.]))))
(;B[rp];W[qp];B[sq];W[sr];B[rr];W[rq];B[ss];W[sp]C[   If Black plays at 1, White can get another ko.]))
(;B[qp];W[rp];B[ro]
(;W[so]
(;B[rq]
(;W[sq]C[   Playing at 1 could soon start a ko.])
(;W[rn];B[rr]C[     White can't capture the single stone.]))
(;B[rn];W[sr]C[     Black 1 is careless, since White will live with 2.]))
(;W[sp];B[sr]
(;W[rr];B[so]C[     White cannot play at 1, since Black 2 will kill the group.])
(;W[rn];B[qn];W[so];B[rr]C[       White still can't gain by playing 1 and 3; Black 4 will kill the       group.]))
(;W[sq]
(;B[rs]
(;W[rr];B[so]C[     This will end in ko, which could be to White's benefit.];W[ss];B[sr];W[qs];B[sp]C[     If White had one more outside dame, he could connect at A and would be     alive. However, he would have to take the two stones.];W[ss];B[rq]C[     And fight the ko.])
(;W[so]
(;B[rr]C[       White can't try to gain a move with 1, because Black will play at 2.])
(;B[rn];W[rr];B[sn]C[         If Black answers at 1, then it is back to the ko.])))
(;B[rr];W[rs]C[       If Black 1, White lives with 2.])))
(;B[rp];W[qp];B[ro];W[rn]
(;B[rm]C[   Black must play at 5, not at "a".];W[qn];B[sn];W[so];B[sp];W[rq];B[sm];W[qm];B[rl];W[sq];B[so];W[rs]C[   White will be able to live with the sequence to 16.]
)
(;B[qn];W[rm]C[     Black cannot cut at 1.]))
(;B[ro];W[rp];B[rn];W[sr]C[   White can live easily with the moves to 4.]))
(;B[pr];W[qo];B[po];W[pp];B[qp];W[qq];B[rp];W[qr];B[rr];W[ms]
(;B[os];W[mo];B[qs];W[no];B[rq]C[   If Black plays at 1, White will sacrifice to squeeze Black and would gain   the capture at A, also reducing this from being a point for Black. This   would not be good for Black.])
(;B[rq];W[os];B[qs]C[     If Black avoids the dame-zumari, White gains by capturing a stone with     2. If Black later takes these two stones and White recaptures, this     would mean that White had gained two points. Also bad for Black.])))
(;W[po];B[qo];W[pp];B[qp];W[ms];B[os]C[   The normal yose would give Black a one point win or leave the score even.]))