3) White could have won even bigger by killing the invasion in the lower left.
4) Black could have established an early lead by surrounding the lower right.
See commentary.
Ed's comments focus on the lower right technique and tactics, which is highlight 4 throughout the commentary.
(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[6.50]TM[600]
PW[Thimblefox]PB[Black]WR[15k]BR[15k]DT[2015-04-06]RE[W+20.50]LT[]NB[14]NW[14]RR[Normal]
;B[qd]BL[599]
;W[dp]WL[597]
;B[nc]BL[584]
;W[pp]WL[593]
;B[dc]BL[569]
;W[de]WL[586]
;B[dd]BL[558]
;W[ce]WL[576]
;B[jq]BL[554]
;W[dj]WL[562]LB[bc:A][fd:C][ee:B]C[KW: I seem to disagree somewhat with Ed on which move to play instead. He chooses A while I would choose B or even C.
This is not an easy matter to discuss so I leave this to a high level player.]
;B[nq]BL[537]
(;W[oq]WL[558]
;B[np]BL[530]C[This seems clever of him, should I avoid kicking and just enclose normally when someone does this? Or maybe I should just react to his K3 stone, and then play elsewhere.
KW: see var]
;W[pn]WL[556]
;B[ql]BL[515]C[KW: good play by Black]
;W[qj]WL[545]C[KW: a daring move and probably a little too daring]
;B[ol]BL[509]
;W[qg]WL[544]
(;B[qe]BL[502]C[KW: Very slack move by Black, see var]
;W[ic]WL[540]C[KW: you understand the concept of miai and making two space extensions. But getting those is not such a great reward. There are often better positions to conquer.]
;B[gc]BL[497]
;W[lc]WL[538]C[KW: Even if invasions involve equivalent options to make a 2-space extension, they're still negative in nature. You could build at the left or the bottom instead, or better, avoid being surrounded at the lower right.]
;B[ne]BL[494]
;W[mf]WL[522]
;B[ro]BL[480]
;W[rp]WL[512]
(;B[rn]BL[478]C[KW: another slack move by Black]
;W[gq]WL[488]C[KW: the lower right is still vulnerable]
;B[cn]BL[463]
;W[co]WL[483]
;B[ck]BL[456]
;W[cj]WL[461]
;B[dn]BL[445]
;W[nn]WL[432]C[The white position is stil thin.]
(;B[op]BL[438]C[KW: See var]
;W[or]WL[416]
;B[nr]BL[435]
;W[nj]WL[400]C[KW: the corner is still thin]
;B[nl]BL[432]
;W[ln]WL[396]
;B[mo]BL[429]
;W[mn]WL[394]
;B[qm]BL[428]C[KW: almost a pass move by Black]
;W[oo]WL[368]LB[nj:A]C[KW: Very good
This concludes my (backwards counted) highlight 4, becayse White is connected and has avoided being surrounded.
Suddenly, the ambitious A becomes a perfect attack on the Black group and this one is in danger of being surrounded.]
;B[lo]BL[417]
;W[ko]WL[364]
;B[kp]BL[415]
;W[jo]WL[359]
;B[lq]BL[403]
;W[pq]WL[329]LB[mk:A]C[KW: Here starts highlight 2
Instead, you could surround Black at A.
The two stones you protect are worth nothing, since Black lives already at the bottom]
;B[ll]BL[388]
;W[jl]WL[312]C[KW: very good. One can see you are a good player.]
;B[dk]BL[373]
;W[ek]WL[311]
;B[el]BL[371]
;W[fk]WL[308]
;B[do]BL[368]
;W[cp]WL[284]
;B[bk]BL[359]
(;W[bj]WL[278]C[KW: Highlight 2 again
See var]
;B[bn]BL[353]
;W[bo]WL[267]
;B[ep]BL[351]
;W[eq]WL[263]
;B[fp]BL[350]
;W[fq]WL[258]
;B[gp]BL[348]
;W[hp]WL[257]
;B[iq]BL[345]
;W[hq]WL[255]
;B[fl]BL[340]
;W[gl]WL[251]
;B[fn]BL[335]
;W[gm]WL[240]
;B[gn]BL[333]
;W[hn]WL[238]
;B[ho]BL[332]
;W[io]WL[237]
;B[go]BL[331]
;W[kj]WL[219]C[KW Very good move
This move surrounds the black group while forming a central moyo]
;B[gf]BL[328]
;W[ge]WL[207]LB[rk:A]C[KW: you concentrate on the moyo, while Black has neglected his group.]
;B[fe]BL[324]
;W[ff]WL[206]C[KW: a daring move. Again you see you are a good player in the making]
(;B[ef]BL[323]C[KW: See var]
;W[fg]WL[192]
;B[ee]BL[322]
;W[gd]WL[182]C[KW: Highlight 1
You concentrate on the moyo, giving up your 2 stones; this is consistent and very strong.]
;B[eg]BL[319]
;W[eh]WL[181]
;B[fh]BL[314]
;W[gg]WL[179]
;B[fd]BL[313]
;W[fc]WL[168]
;B[ec]BL[308]
;W[fb]WL[166]
;B[eb]BL[307]
;W[gb]WL[159]
;B[dh]BL[304]
;W[ei]WL[154]
;B[dg]BL[303]
;W[bg]WL[132]C[(and still save them

)]
;B[bc]BL[290]
;W[hf]WL[88]
;B[cb]BL[283]C[KW: another almost pass move]
;W[rk]WL[73]C[KW very good move
Higlight 2: Black can be killed or at least seriously harassed]
;B[rl]BL[278]
;W[sm]WL[61]C[KW: 1 eye]
;B[sl]BL[274]
(;W[sk]WL[54]C[KW: no need
If you fortify your surrounding position, Black will die]
;B[qk]BL[273]C[So it wasn't that good a move, and then I made a stupid mistake.]
;W[pj]WL[49]
;B[rj]BL[269]
;W[ri]WL[48]
;B[sj]BL[267]C[KW: end of highlight 2.]
;W[si]WL[43]C[KW: a pass move]
;B[qn]BL[248]C[KW: a pass move]
;W[ng]WL[523]C[KW: Highlight 1 again]
;B[mj]BL[222]
;W[mi]WL[517]
;B[lj]BL[221]
;W[li]WL[516]
;B[kk]BL[220]
;W[jk]WL[511]C[Highlight 1]
;B[kl]BL[219]
;W[km]WL[485]
;B[pg]BL[206]
;W[ph]WL[480]
;B[rg]BL[202]
;W[og]WL[467]
;B[qh]BL[196]
;W[qi]WL[460]
;B[qf]BL[192]
;W[pf]WL[455]
;B[pe]BL[189]
;W[qg]WL[453]
;B[rh]BL[187]
;W[me]WL[445]C[Highlight 1 !]
;B[md]BL[182]
;W[ld]WL[444]C[KW: the game is essentially over now
We now focus on the last highlight: the corner invasion]
;B[of]BL[181]
;W[pg]WL[438]
;B[rf]BL[179]
;W[mc]WL[430]
;B[nd]BL[178]
;W[nb]WL[429]
;B[ob]BL[177]
;W[mb]WL[427]
;B[di]BL[168]
;W[fi]WL[399]
;B[bi]BL[167]
;W[ci]WL[388]
;B[aj]BL[165]
;W[bh]WL[354]
;B[ai]BL[139]
;W[ah]WL[326]
;B[ak]BL[134]
;W[ch]WL[322]
;B[ae]BL[130]
;W[bf]WL[318]
;B[bd]BL[122]
;W[be]WL[314]
;B[cd]BL[120]
;W[ea]WL[311]
;B[da]BL[118]
;W[fa]WL[296]C[(a few pass moves in this sequence)]
;B[gh]BL[115]C[KW: in what follows, Black makes many hopeless or nonsensical moves, to which White needlessly responds]
;W[hh]WL[580]
;B[gi]BL[114]
;W[gj]WL[576]
;B[jj]BL[112]
;W[ki]WL[509]
;B[jm]BL[99]
;W[im]WL[482]
;B[om]BL[68]
;W[pm]WL[461]
;B[pl]BL[66]
;W[no]WL[458]
;B[qp]BL[63]C[The next big mistake.]
(;W[qo]WL[444]
;B[qq]BL[55]
;W[po]WL[401]
;B[qr]BL[52]
;W[mk]WL[321]
(;B[ml]BL[39]
;W[lk]WL[317]
;B[ik]BL[24]
;W[il]WL[311]
;B[hj]BL[23]
;W[hi]WL[306]
;B[oj]BL[598]
;W[ok]WL[295]
;B[oi]BL[594]
;W[ni]WL[278]
;B[nk]BL[590]
;W[pk]WL[271]
;B[ji]BL[583]
;W[jh]WL[259]
;B[le]BL[578]C[(many hopeless moves and needless responses again)]
;W[ke]WL[244]
;B[nf]BL[573]
;W[lf]WL[235]
;B[mg]BL[572]
;W[lg]WL[211]
;B[nh]BL[562]
;W[mh]WL[198]
;B[kh]BL[547]
;W[kg]WL[189]
;B[ih]BL[546]
(;W[lh]WL[186]
;B[jg]BL[543]
;W[kh]WL[177]
;B[hc]BL[541]
;W[hb]WL[174]
;B[hd]BL[538]
;W[id]WL[169]
;B[if]BL[535]
;W[ii]WL[577]
;B[jf]BL[531]
;W[ig]WL[567]
;B[sh]BL[529]
;W[pi]WL[555]
;B[na]BL[518]
;W[ma]WL[552]
;B[oa]BL[514]
;W[ir]WL[526]
;B[jr]BL[511]
;W[hr]WL[521]
;B[dr]BL[504]C[Highlight 2: the corner]
;W[dq]WL[519]C[Attacking him straight on seems like a bad strategy, B2 maybe?]
;B[cr]BL[502]
(;W[er]WL[511]C[Hmm, I need to learn how to deal with corner invasions. Even now B2 doesn't seem that bad.
KW: see var]
;B[bq]BL[500]
;W[cq]WL[505]
;B[bs]BL[498]
;W[ar]WL[497]
;B[aq]BL[483]
;W[ao]WL[451]C[I worried about him connecting.]
;B[ds]BL[472]
;W[es]WL[398]
;B[an]BL[590]
;W[fm]WL[330]
;B[em]BL[586]
;W[js]WL[325]
;B[ks]BL[584]
;W[is]WL[324]
;B[lr]BL[582]
;W[ns]WL[244]
;B[ms]BL[579]
;W[os]WL[243]
;B[qs]BL[577]
;W[af]WL[206]
;B[ad]BL[572]
;W[jp]WL[139]
;B[mp]BL[551]
;W[ip]WL[125]
;B[gs]BL[543]C[KW: This is a nonsensical move]
;W[df]WL[102]
;B[cg]BL[519]
;W[cf]WL[89]
;B[ed]BL[518]
;W[ej]WL[86]
;B[gr]BL[499]
;W[br]WL[58]C[Pointless, but I only had 12 seconds to place my stone.]
;B[as]BL[493]
;W[]WL[37]
;B[]BL[493]
;W[]WL[600]TW[ga][ha][ia][ja][ka][la][ib][jb][kb][lb][gc][hc][jc][kc][hd][jd][kd][he][ie][je][le][gf][if][jf][kf][ag][hg][jg][mg][fh][gh][ih][nh][oh][gi][ji][oi][fj][hj][ij][jj][lj][mj][oj][gk][hk][ik][hl][hm][jm][in][jn][kn][fr][gr][fs][gs][hs]TB[aa][ba][ca][pa][qa][ra][sa][ab][bb][db][pb][qb][rb][sb][ac][cc][oc][pc][qc][rc][sc][od][pd][rd][sd][oe][re][se][sf][sg][rk][sk][al][bl][cl][dl][am][bm][cm][dm][rm][sm][en][sn][eo][fo][so][lp][rp][sp][kq][mq][rq][sq][ar][br][kr][mr][rr][sr][cs][ls][rs][ss]
;TW[ga][ha][ia][ja][ka][la][ib][jb][kb][lb][gc][hc][jc][kc][hd][jd][kd][he][ie][je][le][gf][if][jf][kf][ag][hg][jg][mg][fh][gh][ih][nh][oh][gi][ji][oi][fj][hj][ij][jj][lj][mj][oj][gk][hk][ik][hl][hm][jm][in][jn][kn][fr][gr][fs][gs][hs]TB[aa][ba][ca][pa][qa][ra][sa][ab][bb][db][pb][qb][rb][sb][ac][cc][oc][pc][qc][rc][sc][od][pd][rd][sd][oe][re][se][sf][sg][rk][sk][al][bl][cl][dl][am][bm][cm][dm][rm][sm][en][sn][eo][fo][so][lp][rp][sp][kq][mq][rq][sq][ar][br][kr][mr][rr][sr][cs][ls][rs][ss]OS[vincentp])
(;W[bq]LB[bp:A][gr:B]C[White has eyes at A and B
Black will have a hard time making even 1 eye.
]
;B[br]
(;W[ar]
;B[ap]
;W[aq]
;B[ao]
;W[er]C[Black has no eye])
(;W[aq]
;B[ar]
;W[er]
;B[ds]
;W[bs]C[Black has one eye, White has 2.])))
(;W[jg]
;B[ig]
;W[if]))
(;B[lk]
;W[ml]
;B[lm]
;W[mm]))
(;W[qq]))
(;W[oj]C[It needs a strong player now to live with black]))
(;B[he]
;W[gd]
;B[hd]
;W[fd]
;B[fc]
;W[ee]
;B[ed]
;W[fe]
;B[hc]))
(;W[mk]
;B[ml]
;W[pk]
;B[pl]
;W[kk]))
(;B[oo]
(;W[on]
;B[po]
;W[qo]
;B[qn]
;W[qp])
(;W[po]
;B[on]
;W[pm]
;B[pl]
;W[om]
;B[nm]
;W[nl]
;B[mm]
;W[nk]
;B[pj]
;W[pi]
;B[oj])))
(;B[qo]
(;W[qp]
;B[po])
(;W[po]
;B[qp]
;W[qq]
;B[rq])))
(;B[nm]C[Highlight 4
White is surrounded.
]))
(;W[qn]
;B[pr]
;W[qq]
;B[lp]LB[fd:B][ee:A]C[KW: in this variation, Black ends in gote. His position is solid but sente is worth more in this case. Again, I would use it to take the upper hand in the upper left.]))