(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]

;B[pd]
;W[dd]
;B[qp]
;W[dp]
;B[fq]
(;W[cn]C[Best]
;B[kq]
(;W[qj]C[Better than approach from upper left]
(;B[qg]
(;W[qm]
(;B[pn]C[peaceful way]
(;W[ro]C[best way]
(;B[rn]C[korean way]
(;W[qn]
;B[qo]
(;W[rm]C[usual]
;B[rp]
(;W[sn]
(;B[mp]C[Is this necessary, or can black tenuki? Professional conclusion is that this is necessary. See variation.

This is the proper joseki for both.]
(;W[jc]C[most common play]
(;B[cf]
;W[fd]
;B[bd]
;W[qc]
(;B[pc]
;W[qd]
(;B[pe]LB[pb:A][qe:B][re:C]C[white is already alive in this variation, but should consider playing again, otherwise things can get hard, especially if black plays around L17. B is most popular, A is least popular]
(;W[qe]C[most popular, as its sente]
(;B[qb]C[Probably best for black here]
;W[rb]
;B[pb]
;W[qf]
;B[pf]
;W[rg]
;B[rh]C[This is best, creates aji]
;W[qh]
;B[pg]
;W[ri]C[Q12, S17 for later]
(;B[lc]C[Necessary]
(;W[lb]C[Best response]
(;B[kb]
;W[kc]
;B[jb]
;W[ld]
;B[mc]
;W[ib]
;B[mb]
;W[ic]
(;B[cc]C[Has a big follow up at E18]
(;W[dr]C[Rather play a big point than defend]
(;B[hp]
(;W[dc]C[End of joseki])
(;W[oo]LB[po:A]C[Also a way]
(;B[po]C[Good for white, even if white tenuki's]
;W[oq]C[White needs to think about ko threats before playing this move]
(;B[pq]
;W[mo])
(;B[no]
;W[mq]
;B[lq]C[Best reply]
;W[np]
;B[nn]
;W[qr]
;B[rr]
;W[qq]
(;B[rq]
;W[mr]C[white is alive]
;B[qs]
;W[op]C[sente]
(;B[on]
;W[nr])
(;B[os]
;W[on]
;B[om]
;W[nm]
;B[pm]
;W[mo]
;B[mn]
;W[mm]
;B[ln]
;W[ol]))
(;B[mr]
;W[rq]
;B[sq]
;W[on]
;B[om]
;W[op]
;B[pm]
;W[nm]
;B[nq]
;W[or]
;B[ok]
;W[sp]
;B[so]
;W[mo]
;B[mn]
;W[sp]
;B[do]
;W[co]
;B[so]
;W[mm]
;B[ln]
;W[sp]
;B[ep]C[S14 is also big. Theory says black doesn't have enough ko threats, but that's not entirely clear.]
;W[sr])))
(;B[no]C[Good reply from black. ]
(;W[rq]C[tesuji/trick play]
(;B[sp]
;W[oq]
;B[on]
;W[mq]
;B[lq]
;W[np]
;B[mo]
;W[qq]
;B[mr]
;W[or])
(;B[qq]
(;W[sp]
;B[rr])
(;W[rr]
;B[sp]
;W[oq]
(;B[on]
;W[qr]C[white can live this way])
(;B[op]C[This kills white]
(;W[pp]
;B[np]
;W[pq]
;B[qr]
;W[po]
;B[on])
(;W[qr]
;B[pq]
;W[pr]
;B[or]
;W[nq]
;B[nr]
;W[mq]
;B[mr]
;W[lq]
;B[lp])))))
(;W[oq]C[only viable if there is some local aji, eg white stones around J3]))
(;B[op]C[passive reply from black]
;W[no]
;B[np]
;W[po]C[good points for white])))
(;B[eb]C[This variation is not good for black]
;W[iq]C[Very severe invasion]
;B[go]
;W[io]))
(;W[dc]
;B[dr]
(;W[ch]
(;B[df]C[This is correct])
(;B[ef]
;W[cd]
;B[bb]
;W[cb]
;B[bc]
;W[df]C[This cut works (verify)]))
(;W[cq]
;B[fo]
;W[ch]
(;B[df]
;W[fm]C[Vital point])
(;B[dm]
;W[dn]
;B[fm]))))
(;B[dr]C[Also big]))
(;B[mb]
;W[kb]
;B[mc]C[Black is overconcentrated]))
(;W[je]C[Not so good, but playable.])
(;W[cc]C[Pros tend to avoid this exchange, perhaps white wants to develop the left later. See variation for illustration]
;B[ci]
(;W[je]C[Can't tenuki here])
(;W[dr]
;B[hc]
(;W[hd]
;B[ic]
;W[id]
;B[jb]
;W[jd]
;B[kb]
;W[gc])
(;W[id]
;B[hd]
;W[he]
;B[jb]
;W[kb]
;B[ib]
;W[kc]
;B[lb]
;W[ka]
;B[fb]
;W[ge]
;B[db]
;W[jf]C[Black gets life in sente])))
(;W[dr]
(;B[hc]C[Maybe invasion is not good enough at this point]
;W[hd]
;B[ic]
;W[id]
;B[jb]
;W[jd]
;B[kb]
;W[ch]C[This is why that exchange was bad. White can develop the left])
(;B[cc]
;W[dc]C[Now invasion is harder]
(;B[hc]
;W[id]C[No space to live inside])
(;B[ic]C[This is an alternative invasion point. But it should be played later]
(;W[id]C[Only answer]
;B[ib]
;W[jb]
;B[jd]
;W[hd]
;B[kc]
;W[je]
;B[kd]
;W[hb]
;B[kb]
;W[hc]
;B[ja]C[Gote for black, now white can play a big point like C12])
(;W[jd]C[Doesn't work.]
;B[jb]
;W[kb]
;B[ib]
;W[kc]
;B[id]C[Black can now use that wall])))))
(;B[rc]
;W[rd]
;B[sb]
;W[sc]
;B[ra]))
(;B[qf]
;W[pb]C[good, with K17 there]
;B[ob]
;W[qb]
;B[nc]))
(;W[pb]C[Not popular]
;B[ob]
;W[qb]C[Maybe black can tenuki here, as his group is flexible]
(;B[qe]C[mistake]
;W[nb]
;B[oa]
;W[nc]
;B[oc]
;W[re]
;B[rf]
;W[sd])
(;B[nc]
;W[qe]
;B[qf]))
(;W[re]
;B[lc]
;W[qf]
;B[pf]
;W[pg]
;B[ph]C[big ko]
;W[og]
;B[rg]
;W[oh]
;B[qb]
;W[rb]
;B[rc]
;W[rd]
;B[rf]
;W[qe]
;B[sb]C[big ko]))
(;B[qe]C[not good for black.]
;W[re]
;B[rf]
;W[pe]
;B[qf]
;W[pb]
;B[ob]
;W[qb]
;B[nc]
(;W[rd]
;B[oe]C[black strength is useless])
(;W[oe]C[White can consider this fighting variation]
(;B[nd]
;W[rd]
;B[nf]
;W[pg])
(;B[rd]
(;W[nd]
;B[oc]
;W[mc]
;B[mb]
;W[lc])
(;W[rc]
;B[se]
;W[nd]
;B[oc]
;W[mc]
;B[mb]
;W[lc]C[both sides can live]
;B[na]
;W[pa]
;B[oa]
;W[ra]
;B[lb]
;W[kb]
;B[la])))))
(;B[qd]C[Not a good way to block]
;W[pc]
;B[oc]
;W[ob]
(;B[nc]
;W[nb]
;B[mc]
;W[cc]
;B[ci]
;W[rd]
;B[re]
;W[rc])
(;B[nb]
;W[nc]
;B[od]
;W[mb]
;B[pb]
;W[na]
;B[qb]
;W[cg]C[Not good enough for black])))
(;B[oc]C[Too small, given what is happening on left]))
(;W[qc]C[Also ok]
;B[pc]
;W[qd]
;B[pe]
;W[jc]C[White already alive in corner])
(;W[kc]
(;B[cf]C[With white at L17, this direction is wrong]
;W[fd]
;B[bd]
;W[qc]
(;B[qd]
;W[pc]
;B[oc]
;W[ob]
;B[nb]C[double hane doesn't work]
;W[nc]
;B[od]
(;W[mb]C[This is a mistake by white]
;B[pb]
;W[na]
;B[qb]C[OK for both sides])
(;W[pb]C[This is possible for white. Black can't extend]))
(;B[pc]
;W[qd]
;B[pe]
;W[qe]
;B[qb]
(;W[pb]
;B[qf]
;W[pf])
(;W[rb]
;B[pb]
;W[qf]
;B[pf]
;W[rg])))
(;B[fc]C[This is correct]
(;W[ec]
;B[fd]
;W[df]C[The high move is vital for the upcoming fight]
;B[ic]
;W[nc]
(;B[ob]C[This is the best choice compared to P17 or Q17]
(;W[je]
(;B[kd]C[Ladder works for white])
(;B[ne]C[Aims at L16 cutting point]
(;W[le]C[Good exchange for black]
;B[he])
(;W[gb]C[Good move]
(;B[fb]
;W[hc]
;B[hd]
;W[ib])
(;B[ie]
(;W[fb]
;B[jf]
;W[ke]
;B[if]
;W[nb]
;B[ch])
(;W[if]
;B[fb]
;W[hc]
;B[hd]
;W[ib]
;B[jb]
;W[jc])
(;W[jf]
;B[fb]
;W[hc])))))
(;W[nb]C[Too slow]
;B[ie])
(;W[ke]C[Not enough pressure on black]
;B[ie]
;W[kg]
;B[ig]))
(;B[pc]
;W[je]
;B[he]
;W[ig])
(;B[oc]
;W[nd]C[Not good enough for black. R17 is severe]))
(;W[hc]
(;B[cc]
;W[dc]
;B[cd]
;W[de]
;B[db]
;W[eb]
;B[cb]
;W[ec]
;B[cf]
;W[qc]
;B[qd]
;W[pc]
;B[oc]
;W[ob]
;B[nc]
;W[nb]
;B[mc]
;W[rd]C[Should not ignore this move.]
;B[re]
;W[rc]
;B[id])
(;B[oc]
;W[ec]))))
(;W[nc]C[Not popular]
;B[pc]
;W[kc]
;B[cf]
;W[fc]
;B[bd]
;W[cc]
;B[ci]C[Good result for black]))
(;B[fc]
;W[hc]
;B[cc]
;W[dc]
;B[cd]
;W[de]
;B[db]
;W[eb]
;B[cb]
;W[ec]
;B[cf]
;W[mq]C[severe - now black is split]
;B[oq]
;W[mo]
;B[ip]
;W[oo]
;B[po]
;W[er]
;B[fr]
;W[qc])
(;B[po]))
(;W[lp]C[Is it necessary to capture?]
;B[kp]
;W[lo]
;B[so]
;W[pm]
;B[on]
;W[ko]
;B[ip]
;W[io]
;B[hp]))
(;W[rp]C[Can't do this]
(;B[rq]C[no good])
(;B[rm]C[ladder situation]
;W[rl]
;B[ql]
;W[pm]
;B[rk]
;W[qq]
;B[pq]
;W[qr]
;B[pr]
;W[sq]
;B[pk])))
(;W[qo]
;B[qn]
;W[po]
(;B[oo]
;W[pp]
;B[op]
;W[pq]
;B[oq]
(;W[or]
;B[nr]
;W[pr]
;B[nm]
;W[nj]
;B[lj])
(;W[on]
;B[pm]
;W[or]
;B[nr]
;W[pr]
;B[nn]
;W[nq]
;B[mq]
;W[np]
;B[om]
;W[no]
;B[on]
;W[mr]
;B[mo]
;W[ns]
;B[pi]))
(;B[on]
;W[pp]
;B[np]
;W[or]
;B[oj])))
(;B[qo]C[japanese way]
;W[rp]
(;B[rq]
;W[qn]
;B[pq]
;W[qr]
;B[qq]
;W[ol]LB[mq:B][nq:A]C[Good for white

later A or B is big for white])
(;B[rn]
;W[qq]C[must]
(;B[pq]C[mistake]
;W[rq]C[Better than R2. Prevents black T5 sente]
;B[qn]
;W[pr]
;B[oq]
;W[or]
;B[nq]
;W[oj])
(;B[qn]
;W[pq]
;B[nq]
;W[oj]C[reasonable result for white])))
(;B[pm]C[chinese way, but really only works if black is at R12]
(;W[ql]C[mistake])
(;W[qo]
;B[po]
;W[ql]
;B[pp]C[s4 is risky]
(;W[ok]C[honte
d2 better than f5, according to Jack])
(;W[as]
;B[pk])
(;W[rp]
;B[pk]C[important peep (but R13 must be at R12)])))
(;B[rp]
(;W[qo]
(;B[po]
;W[pp]
(;B[op]
;W[pq]
(;B[oq]
;W[qq])
(;B[pm]
;W[ql]
;B[qq]
;W[oq]
;B[nq]))
(;B[pq]C[good for white]
;W[op]
;B[oq]
;W[np]
;B[nq]
;W[mp]
;B[mq]
;W[lp]
;B[pm]
;W[ql]
;B[mm]
;W[kp]
;B[jq]
;W[jp]
;B[iq]
;W[km]C[black is almost dead]))
(;B[pp]
(;W[po]C[Can't do this]
;B[oo]
(;W[on]C[wrong cut]
;B[pm]
;W[ql]
;B[no]C[ok for black])
(;W[op]
(;B[oq]
;W[np]
;B[nq]
;W[mp]
;B[mq]
;W[lp]
;B[on]
;W[ln])
(;B[np]
;W[oq]
;B[nq]
;W[pr]
(;B[nr]
(;W[rr]
;B[qr]
;W[qq]
;B[pq]
;W[or]
;B[rq]
;W[qs]C[ko. but black will leave it alone, and play outside. white needs three moves to capture the black stones definitively, so its fine for black. black can leave it until black has a big ko threat.])
(;W[qr]C[seki but in gote for white (verify)]))
(;B[qr]
;W[nr]
(;B[mr]C[not possible, if ladders work for white]
;W[no]
;B[on]
;W[nn]
(;B[pq]
;W[or]
;B[ns]
;W[om]
;B[ps]
;W[pm])
(;B[nm]
;W[mq]
;B[mp]
;W[lq]
;B[lr]
;W[lp]
;B[mo]
(;W[kp]C[mistake (verify)])
(;W[kr]
;B[jr]
;W[kp]
(;B[jq]
;W[mn])
(;B[pq]
;W[or]
;B[ns]
;W[jq]
;B[ps]
;W[ls]C[sente for white]
;B[os]
;W[eq]))))
(;B[mq]
;W[rr]
(;B[qs]
;W[rq]
;B[qq]
;W[sp]
;B[rs]C[ko (verify)])
(;B[pq]C[failure])
(;B[rs]C[correct]
;W[on]
;B[no]
(;W[qq]C[not good enough]
;B[qs])
(;W[om]
;B[sr]C[better for white. black has 25 points, and no remaining bad aji. but white has sente and a strong group.
even result]
;W[jc])))))
(;B[pm]C[best first move]
;W[ql]
;B[np]
;W[oq]
;B[nq]
;W[pr]
;B[qr]
;W[nr]
;B[mr]C[now black can play here, because black has extra liberties, and the ladders work for black.])))
(;W[pm]C[best move for white]
;B[on]
;W[lp]C[good for white])))
(;W[pm]C[best play]
(;B[on]C[Not so good]
;W[qo]
;B[pp]
;W[lp]
;B[kp]
;W[lo])
(;B[om]C[must]
(;W[ol]
;B[nm]
;W[lp]
;B[kp]
;W[lo]
;B[nl]C[ok for both sides])
(;W[on]
(;B[po]
;W[nn]
;B[ol]
;W[np]
;B[pq]
;W[ko]
;B[ip]
;W[pk]C[good for white. white's group has better shape than black's])
(;B[qn]
;W[rn]
;B[op]
;W[nn]
;B[ol]
;W[np]
;B[nq]
;W[oq]
(;B[pq]C[bad]
;W[oo]
;B[pp]
;W[mq]
;B[or]
;W[pk]
;B[ml]
;W[ln]C[no time for atari
reasonable result for white
later, atari at O2 is attractive for white])
(;B[pp]C[best answer]
;W[mq]
;B[nr]
;W[mr]
;B[mp]
;W[no]
;B[or]
;W[lp]
;B[rl]
(;W[rm]
;B[qk]
;W[pk]
;B[rj]
;W[pl]
;B[ml]
;W[pj]
;B[qi]
;W[nj]
;B[kl]
;W[kp]C[Best variation for both sides after the cut])
(;W[rk]C[doesn't work for white]
(;B[ql]C[doesn't work])
(;B[pk]C[only move]
(;W[rm]
;B[qk])
(;W[ql]
;B[qk]
;W[rm]
;B[rj]
;W[sl]))))))))))
(;W[qn]C[Not so great for white]
;B[qo]
(;W[ol]
;B[on]C[early way, but not good enough for white]
(;W[lp]C[dangerous]
(;B[pk]
;W[qk]
;B[pl]
;W[pm]
;B[om])
(;B[kp]
;W[lo]
(;B[mr]C[Passive play. Must rather attack at Q9])
(;B[pk]
;W[qk]
;B[pl]
;W[pm]
;B[om]
(;W[ql]C[not good]
;B[nl]
;W[ok]
;B[pj]
;W[pi]
;B[oj]
;W[nk]
;B[oi]
;W[mk]
(;B[ph]C[too passive]
;W[qi]C[white is alive])
(;B[qi]C[must]
;W[ph]
;B[qh]
;W[ro]
;B[rp]
;W[so]
;B[oh]C[very good for black]))
(;W[nl]C[an option, but it doesn't end well.]
(;B[ok]C[correct shape]
;W[ql]
;B[pi]
;W[pj]
;B[oj]
;W[oi]
;B[mk]
;W[ph]
;B[mm]
;W[ko]
;B[ip]
;W[io]
;B[hp]
(;W[pq]C[Correct peep.]
;B[mr])
(;W[lq]
;B[oq]))
(;B[pj]C[bad. black ends up with weak group]
;W[pi]
;B[oj]
;W[ri])))))
(;W[ko]C[Not so good as a reduction move]
;B[lo]))
(;W[pm]C[Better]
;B[on]
;W[lp]
;B[kp]
;W[lo]
;B[om]
;W[oj]
;B[ol]
;W[pk]
;B[jn]))
(;W[pm]
;B[qn]
;W[om]C[Must]
;B[on]
;W[nm]
;B[nn]
(;W[mm]
;B[lo]
;W[qq]
;B[rq])
(;W[lp]
;B[kp]
;W[ln]
;B[mp]
;W[mn]
;B[lq]C[OK for black, as H3 area becomes territory])
(;W[iq]
;B[mm]
;W[eq]))
(;W[qq]C[A possible way]
;B[pq]
;W[pm]C[Black will tennuki now]))
(;B[pk]C[fighting
]
;W[qk]
(;B[pn]
;W[pl]
(;B[cf])
(;B[fc]
;W[hc]
;B[cc]
;W[dc]
;B[cd]
;W[de]
;B[db]
;W[eb]
;B[cb]
;W[ec]
;B[cf]
(;W[pq]C[Best invasion point]
;B[qq]
;W[mq]
(;B[pr]C[Best move for black]
;W[mo]
;B[ko]
;W[mm])
(;B[ko]
(;W[mo]
;B[km]
;W[mm])
(;W[pp]C[Good for white]
;B[qn]
;W[ro]
(;B[qo]
;W[mo])
(;B[rn]
;W[qr]
;B[rr]
;W[qo]))))
(;W[iq]
(;B[fo])
(;B[ko]
;W[eq]
;B[fp]
;W[io]
;B[fm]C[Because white stones are further away, this is ok. If white is even weaker on the right, E6 is OK. If white stones are on H, then one stone jump is best]
;W[im]C[Hard fight for both sides])
(;B[dr]
;W[eq]
;B[er]
;W[fp]
(;B[gq]
;W[gp]C[C12 becomes big for white])
(;B[gp]
;W[gq]
;B[fr]
;W[hp]
;B[go]
;W[fo]
;B[gn]
;W[in]C[Hard for black]))
(;B[dq]C[Also bad for black (verify)]))
(;W[qc]
;B[pc]
;W[qd]
;B[pe]
;W[kc]C[best]))
(;B[ol]
(;W[iq]C[Can't tenuki]
;B[pm]
;W[ql]
;B[ko]
;W[qc]
;B[pc]
;W[qd]
;B[pe]
;W[qe]
;B[qf]
;W[pb]
;B[ob]
;W[qb]
;B[nc])
(;W[ok]
;B[nk]
(;W[pj]C[Best move for white]
;B[om]C[Usual joseki]
(;W[jc]C[Too slow, not urgent. Black's position is open but full of potential]
;B[fo]C[Big moyo])
(;W[hp]C[Decent move, in Jack's opinion]
;B[fo]
;W[hn]LB[rd:C][fm:A][ko:B]C[Makes miai of A and B]
;B[fm]
;W[ko]
;B[mp]
;W[hl]C[Common variation])
(;W[ko]
;B[ip]C[No good move for white]
(;W[lq]C[Not good for white]
;B[lp]
;W[kp]
;B[jq])
(;W[mo]
(;B[mq])
(;B[lp]
;W[mm]
(;B[ml]
;W[mp])
(;B[np]C[Maybe this is better]
;W[nl]
;B[mk]C[Black has a better position that white, despite having fewer stones in the center]))))
(;W[lp]C[Better]
(;B[lq]
(;W[mp]
(;B[kn]C[Dubious]
;W[kp]
;B[jp]
;W[mq]
;B[iq]C[White is happy now]
;W[pq])
(;B[jo]C[No use]
;W[lm]
;B[jm]
;W[ml]
;B[nl]
;W[pq]
;B[qq]
;W[pp]
;B[qo]C[Important to avoid S5 tesuji]
;W[mq])
(;B[kp]C[Best move]
(;W[lm]C[Can't do this]
;B[mn])
(;W[ln]
;B[ko]
;W[mm]
(;B[ml]
;W[jm])
(;B[jm]C[Now the knight's move. This is good for black]
;W[mk]
;B[nj]))
(;W[mn]C[Also not so great]
(;B[ml]
;W[ko]
;B[jo]
;W[kn]C[Too easy for white])
(;B[lo]C[severe]
;W[mo]
;B[ml]
(;W[ko]
(;B[kn])
(;B[ln]
;W[lm]
;B[kn]
;W[mm]
;B[jo]))
(;W[pp]
;B[qq]
;W[oq]
;B[qo]
;W[km]
;B[go]
;W[ko]
;B[jo]
;W[kn]
;B[dr]
;W[ck]
;B[fc]
;W[cf]
;B[db]C[Black is better here, but it's white's move, and with komi, it's pretty even still])))))
(;W[np]C[not here]
;B[lo]))
(;B[kp]
;W[lo]
;B[ko]
;W[ln]
;B[mr]
;W[kn]
;B[jn]
;W[jm]
;B[in]
;W[kk]C[OK for white])))
(;W[om]C[Pro opinion is that this is not good]
(;B[nl]
;W[pm]
;B[oj]
;W[op])
(;B[oj]C[Important]
(;W[pm]
;B[np])
(;W[nl]
(;B[pm]C[Not feasible, a ko that cannot be fought]
;W[ok]C[Black has no big threats]
;B[do]
;W[pj]
;B[co]
;W[ep]C[E4 can survive, and invastion at P4 is severe])
(;B[nm]
;W[ok])
(;B[ok]C[Ends in gote, and becomes heavy]
;W[pm]
;B[op]
;W[mm]
;B[pi]
;W[jc])
(;B[ml]C[Best way for black. Makes the ko light for black]
(;W[ok]C[Best move]
;B[do]
(;W[pj]
;B[co]C[N8 in a better position than the other variations])
(;W[co]
;B[ol]
;W[nm]
(;B[pm]C[Preseve this move until threats are better]
;W[ok]
;B[dq])
(;B[mm]C[Most aggressive black response]
(;W[ok]C[Played in pro games, but white can do better]
;B[nn])
(;W[no]C[Can't do this]
;B[nn]
;W[on]
;B[pm]
;W[ok]
;B[oo]
;W[mn]
;B[ol]
;W[nn]
;B[ql])
(;W[oo]
(;B[no]C[Does not work]
;W[po])
(;B[on]
;W[nn]
;B[no]
;W[mn]C[Still good for white]
;B[mo]
;W[ln]
;B[po]
;W[ok])
(;B[po]
;W[ok]C[Best for white]
;B[op]
;W[no]
;B[np]
;W[mo]
;B[mp]
;W[ko]
;B[ol]
;W[pm]
;B[oh]C[Reasonable for black])))
(;B[np]C[Probably best way for black]
;W[ok]
;B[fc]
;W[cf]
;B[ol]
;W[pm]
;B[jd]C[White can invade at R3 later. Black central influence is good])))
(;W[nm]
(;B[mm]C[Aggressive]
;W[pm]
;B[np])
(;B[np]C[peaceful])))))))))
(;B[pm]
(;W[pl]
;B[ol]
;W[ql]
;B[pn]C[Not good enough for white])
(;W[qn]C[Only move for white]
;B[pn]
(;W[qo]
;B[po]
(;W[pp]C[good fight for black]
;B[qq]
(;W[op]C[No good for white, this]
;B[or]
;W[mp]
;B[nq]
;W[np]
;B[ql]
;W[rl]
;B[pl]
(;W[pj]
;B[oj])
(;W[rn]
;B[pj]))
(;W[pq]
;B[pr]C[Vital]
;W[or]
;B[qr]
(;W[nq]C[No good]
;B[np]
;W[mq]
;B[mp]
;W[lq]
;B[kp]
;W[kr]
;B[jr]
;W[lr]
;B[lp]
;W[rp]
;B[rq]
;W[ro]
;B[ps]
(;W[rs]
;B[os]
;W[ns]C[black wins (verify)])
(;W[os]
;B[op]
;W[oq]
;B[ks]
;W[ms]
;B[rs]))
(;W[np]
;B[ql]
;W[rl]
;B[pl]
(;W[rn]
(;B[lp]C[Vital point, must not live yet. Note black can live in two ways, either at S4, or O2.
This makes strong shape]
(;W[nq]
;B[rp]
;W[nn]
;B[mo]
;W[no]
;B[mm])
(;W[nn]
(;B[op]C[This can be played anytime]
;W[oq]
;B[oo]
;W[nq]
;B[no])
(;B[rp]
;W[mq]C[Needed to avoid P4 atari]
;B[pj]
;W[qi]
;B[pi]
;W[mm]
;B[km]
;W[mk]
;B[kk])))
(;B[rp]C[Too slow]
;W[lp])
(;B[lo]C[Riskier. This is best ONLY if black is already alive in corner.]
;W[lq]))
(;W[lp]C[Good point, but white can't play this now.]
;B[rk]
;W[rm]
;B[rj]
;W[rp]
;B[rq]
;W[ro]
;B[nr]
;W[nq]
;B[os]
;W[mr]
;B[oq]
;W[op]
;B[or]
;W[sn]
;B[kp]
;W[ln]
;B[qi]))))
(;W[rp]
(;B[rq]C[ok]
;W[qq]
;B[pp]
;W[rr]
;B[ql]
;W[rl]
;B[pl]
;W[rn]
;B[pq]
;W[qr])
(;B[qq]C[ok])))
(;W[lp]C[Aims to be in the vital point for some of the other sequences. But also not good enough]
;B[kp]
(;W[qo]
;B[po]
;W[pp]
;B[qq]
;W[pq]
;B[pr]
;W[or]
;B[qr]
;W[np]
;B[ql]
;W[rl]
;B[pl]
;W[rn]
;B[lo]
;W[mo]
;B[ln]
;W[lq]
;B[kr]
(;W[rp]C[White can't do this (black wins by one liberty, verify)])
(;W[mr]
;B[rp]
;W[mm]
(;B[mn]
;W[nn]
;B[nm]C[Not good]
;W[nl]
;B[om]
;W[op])
(;B[lm]
;W[nm]
(;B[pj]C[There is a tesuji that can be played before this.]
;W[qi]
;B[pi])
(;B[nq]
;W[nr]C[Only one eye]
;B[pj]
;W[qi]
;B[pi]
;W[mj]
;B[ll]
;W[ni]
;B[qh]
;W[rh]
;B[og]))))
(;W[lo]
;B[qo]C[Very big]))
(;W[rp]C[This is the best move. Generally white will get sente from this.]
(;B[rq]
;W[ro]
;B[qq]
;W[hp])
(;B[po]
;W[qq]
;B[pq]
;W[rq]
;B[pr]
;W[hp])
(;B[ql]
;W[rl]
;B[pl]
;W[qo]
;B[po]
;W[pp]
;B[qq]
;W[pq]
;B[rq]
;W[ro]
;B[pr]
;W[or]
;B[qs]
;W[nq]
;B[rr]
;W[no])
(;B[qq]
;W[hp])))
(;W[pn]
;B[qn]
(;W[pl]
;B[om]
;W[ol]
;B[nm]C[Black should avoid playing S7, to preserve the possibility of forcing white to connect there later.])
(;W[rm]
(;B[po]
;W[on]
;B[om]
;W[nn])
(;B[qo]C[Not good enough]
;W[on]
(;B[op]
;W[no]
;B[mq]
;W[pl]
;B[om]
;W[nl])
(;B[om]
;W[op]))
(;B[on]C[No good]
;W[po]
;B[qo]
;W[oo])
(;B[om]C[Best (says book, Jack disagrees)]
(;W[po]
;B[qo]
;W[pp]
;B[pq]
;W[oq]
;B[pr]C[Good fight for black])
(;W[qo]
;B[on]
;W[rn]
(;B[po]
(;W[pp]
;B[qn]
;W[ro]
;B[op]
;W[pq]
;B[oq]
;W[pr]
;B[fo]C[Book sequence, but white is doing well here])
(;W[rp]
;B[qn]
;W[ro]))
(;B[pp]
;W[rp]
;B[rq])))
(;B[rn]
;W[on]
;B[pl]
;W[op]
(;B[pq]C[too slow]
;W[pj]
;B[nl]
;W[oq])
(;B[pj]
;W[qi]
;B[ql]
;W[rl]
;B[sm]
;W[sk]
;B[oh]
;W[qq]
;B[rq]
(;W[rr]
;B[pq]
;W[qr]
;B[pp]
;W[oq]
;B[pr]
;W[or]
;B[os]
;W[rp]
;B[nr]C[good result for black])
(;W[pq])
(;W[pp]
;B[ro]
;W[qr]
;B[rr]
;W[rs]
;B[sp])))))
(;W[pj]
;B[qn]
;W[pl]
;B[om]C[good for black]))))
(;W[pm]C[A way to avoid some of the other variations]
(;B[op]C[Common way]
;W[jc]C[Treat group on right lightly])
(;B[qn]
(;W[qm]C[can't do this])
(;W[qq]
;B[pq]
;W[pp]
(;B[oq]C[Not so good]
;W[qm]C[Too nice for white]
;B[rp]C[sente for white])
(;B[po]
;W[op]
;B[oo]
;W[np]
;B[qr]
;W[rq]
;B[or]
;W[qm]C[Recent professional sequence, unclear on whether its good or not]
;B[no]
;W[mp]))))
(;W[rn]C[Odd, but common]
;B[po]
;W[pm]
;B[mp]))
(;B[ql]C[Less popular way]
;W[qf]
;B[nc]
;W[op]
;B[pn]
;W[qq]
;B[rq]
;W[pq]
;B[rr]
;W[mq])
(;B[qh]C[Too close, but possible if you play Q9 after R7]
;W[qm]
(;B[pn]
(;W[qn]
;B[qo]
;W[ol]
;B[on]
;W[oj]
;B[lo]
;W[qf])
(;W[ro]C[Same result as before. R12 too close]
(;B[pm]
(;W[ql]
;B[pl]
;W[qo]
;B[po]
;W[pp])
(;W[qo]
;B[po]
(;W[pp]C[overplay]
(;B[rp]C[Doesn't work]
;W[ql]
;B[pq])
(;B[qq]C[Best reply]
(;W[ql]
;B[op])
(;W[op]C[White must fight, but this way is hard]
;B[ql]
;W[rm]
;B[or])
(;W[pq]
;B[pr]
;W[or]
;B[qr]
;W[np]
;B[ql]
;W[rm]
;B[no]
;W[mp]
;B[mo]
;W[lp]
;B[rl]C[black is alive in corner (prove this)])))
(;W[ql]C[correct])))
(;B[rn]
;W[qn]
;B[qo]
;W[rm]
;B[rp]
;W[sn]
;B[mp]
;W[nc]
;B[pc]C[R14 is a worry for black, so R12 is dubious.]
;W[kc])))
(;B[pk]
;W[qk]
;B[pm]))
(;B[qf]C[Too far, not enough pressure on white])
(;B[pk]C[Playable, but too complex]))
(;W[nc]C[Not so good]
;B[pf]C[best answer]
(;W[pb]
;B[pj])
(;W[jd]
;B[pj]))
(;W[pj]C[No research on this move]))
(;W[dn]C[Not so good. Later on black can play at C8]))