(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[6.50]
PW[Juyong Koh]PB[James Sedgwick]
;B[pd]
;W[dp]
;B[pp]
;W[dd]
;B[fq]
;W[cn]
;B[dr]
;W[cq]
;B[iq]
;W[qf]
;B[qh]
;W[qn]
;B[qk]
;W[nq]
;B[np]LB[qq:A]TR[qk][iq]C[This move is a bit passive for black.  Black should fight with A, which is reasonable since the triangle stones are there to help.  See the end of the Joseki for a description of why the result is not good enough.]
;W[mp]
;B[no]
;W[qq]
;B[oq]
;W[qp]
;B[mq]LB[ql:A][ro:B][hp:C]TR[qk]SQ[iq]C[First black would like triangle to be at A, allowing black to play B.  White would not choose this sequence however if black had the stone at A.

Aside from this the square stone makes black's positions at the bottom too flat. If it were at C this result would be reasonable for black.]
;W[nd]
;B[pf]
;W[pg]
;B[qg]
;W[pc]
;B[qe]
;W[qc]
(;B[ic]LB[lc:A]C[Before this black should force with A.  See the variation.]
;W[kc]
;B[fc]
;W[ec]
;B[fd]
;W[df]LB[cf:A]TR[fc][fd]C[This move is aiming at the triangle group, but it does give black a natural way to enter the left side.  A more territory oriented strategy with A would also be reasonable.]
;B[ch]
;W[ck]
;B[ce]
;W[de]
(;B[cd]LB[bd:A]TR[ch]SQ[ge][he][gf][hf]C[This move takes the corner, planning to sacrifice triangle.  However, since white has forcing moves in the square area against black's group the territory around triangle can become large.  Given that black it seems better for black to play A (see the variation).]
;W[cc]
;B[bc]
;W[cf]
;B[bf]
;W[bg]
;B[be]
;W[cg]
;B[bb]
;W[cb]
;B[ba]
;W[gf]
;B[if]
;W[hh]
;B[hj]LB[fm:B][fo:A][hp:C]TR[ch]SQ[hj]C[Black reduces since the territory with triangle is getting too large.  However since w has the forcing sequence starting with H4(C) this is probably not good.   Instead black should jump to A.  If white answers with B then black can reduce with H10(square).]
;W[jh]
;B[kb]
;W[lc]
;B[jc]
;W[hp]LB[hq:A]TR[hj]C[Black should probably answer this at A, although this forcing sequence is painful for black, making triangle very lonesome (See the variation). In the game black tries to counter attack]
(;B[fo]
;W[hq]
;B[gn]
;W[lq]
;B[nr]
;W[ip]
;B[jr]LB[jp:B][hr:A]TR[iq]C[James: I thought this rescues triangle, making mia of A and B.  If so this fight is reasonable. However....]
;W[jq]
;B[ir]
;W[fr]C[I missed this tesuji.  Black has no good answer.  See the varations for other black answers that don't give a good result]
(;B[eq]
;W[kr]
;B[jp]
;W[kq]LB[hr:A]C[Black now chooses to play H2(A) and expand the sacrifice to allow a squeeze in the center.  However this is gote, and white's large  life at the bottom in the midst of what was a black area gives white a big lead.]
;B[hr]
;W[gr]
;B[gq]
;W[hs]
;B[io]
;W[ho]
;B[hn]
;W[jo]
;B[in]
;W[lb]
;B[ja]
;W[he]
;B[ie]
;W[hd]LB[fb:A][ib:B][hc:C]TR[fr]C[Here black makes a fatal error.  Before anything else they must force with A threatening to connect.  They can then play something like B or C to live. In the game black missed this forcing move, and was not given another chance.

James: I of course I knew F18 was sente to connect and would allow my group life, but I missed that correct timing required it now.  To some extent I was just going through the motions now, playing some more moves to regain my equilibrium after missing F2(triangle) in my reading. I didn't expect to recover from the loss at the bottom.]
;B[hc]
;W[ib]
;B[hb]
;W[fb]
;B[gb]
;W[eb]
;B[kf]
;W[ke]LB[id:A]C[Now with the cut at A pending white has too many problems.  They played on for a few more moves, but the group dies.])
(;B[kq]
;W[eq]
;B[fp]
;W[gr]TR[hj][gn][fo][fp][fq]C[White has a large corner, and the triangle stones are floating with no base.  This is a disaster for black.])
(;B[gr]
;W[hr]
;B[er]
;W[kr]TR[iq][ir][jr]C[This triangle stones are still captured.]))
(;B[hq]
;W[fp]
;B[jj]))
(;B[bd]
;W[cd]
;B[bf]
;W[bc]
;B[eh]LB[bb:A]C[black can still aim at the ko at B18 later.]))
(;B[lc]
;W[rf]
;B[re]
;W[of]
;B[pe]
;W[nb]LB[fc:B][ic:A]TR[nb][lc]C[Now black can choose A or B, they have already benefited from making the triangled exchange.]))