Fedya wrote:
- in the centre, there's a sente move, that will later earn you a few points
I hope you're talking about K7.
J9 threatens to cut off the White lump. Later, White will be able to capture the two stones to the left.
Quote:
- White's smallest and weakest group is the lower right; can you use sente there to your advantage?
S6 is gote, so I should play S1?[/quote]
How about S7, then S1?
Quote:
- there is aji in the lower left white territory, in two places, which you can perhaps combine
I tried E5 in the game. It doesn't work, because after white responds with E6, Black has to defend above or else White will play E8. (White actually missed E8 in the game.)
At B7 there is aji. You can almost use it for free first. Then play the clamp at C2. If White descends, you push up and use the B7 stone to create a living group. This is a useful tesuji to remember.
If White lets you cross under, he will lose a lot of territory.
Quote:
- at the top there is a local sente endgame move we all know
I don't think the ogeima at N19 is sente.
I do, locally it is and must be.
Quote:
How to play these areas, in which order, to keep sente and squeeze the most profit out of the whole board?
See below, the variation from 148 onwards. Of course, this is easy post game analysis, but it can show you some things to consider next time.
(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.50]TM[1200]OT[5x60 byo-yomi]
PW[squidgepig]PB[Fedya]WR[5k]BR[6k]DT[2016-10-31]PC[The KGS Go Server at http://www.gokgs.com/]RE[W+Resign]
;B[pd]BL[1196.803]
;W[dp]WL[1192.411]
;B[pq]BL[1191.615]
;W[ec]WL[1189.637]
;B[fq]BL[1186.6]
;W[dn]WL[1186.515]
;B[jp]BL[1178.191]
;W[cd]WL[1167.667]
;B[ci]BL[1169.636]C[This both stops White from making good shape with the two stones at the top, and serves as a wedge.]
;W[ck]WL[1162.228]
;B[cf]BL[1149.907]
;W[dh]WL[1142.708]
;B[ch]BL[1137.5]
;W[df]WL[1137.594]
;B[dg]BL[1108.042]
;W[eg]WL[1133.971]
;B[cg]BL[1105.971]
;W[ef]WL[1123.023]
;B[di]BL[1093.275]
;W[nc]WL[1111.157]
;B[qf]BL[1059.87]C[I thought about the pincer, but rejected it because after the joseki White would play a wedge around R10, and then where would I be?]
;W[po]WL[1092.809]
;B[np]BL[1015.859]C[Here, however, I thought even longer and harder about a pincer before deciding on playing something I thought would work well with my stones on the bottom.]
;W[jd]WL[1086.777]
;B[qm]BL[993.529]C[White tenukis and lets me play a double approach!]
;W[pm]WL[1081.234]
;B[ql]BL[971.035]
;W[qn]WL[1035.862]
;B[qi]BL[956.889]
;W[of]WL[1008.846]
;B[nd]BL[922.597]C[I thought about M17, or trying to split on the other side, or keeping up the attack on the stones in the bottom right. In short, I just didn't know what to do. I have a feeling this move is a problem, considering how much White winds up with on the top.]
;W[od]WL[994.921]
;B[oe]BL[919.366]
;W[oc]WL[992.247]
;B[ne]BL[916.604]
;W[pf]WL[967.968]
;B[pe]BL[893.094]
;W[qg]WL[954.262]
;B[pg]BL[884.257]
;W[og]WL[935.73]
;B[ph]BL[881.525]
;W[qe]WL[921.269]
;B[rf]BL[867.962]
;W[re]WL[918.887]
;B[rg]BL[862.345]
;W[qc]WL[908.246]
;B[pc]BL[849.941]
;W[qb]WL[894.376]
;B[pb]BL[838.969]
;W[mc]WL[891.562]
;B[qd]BL[826.751]
;W[rd]WL[888.811]
;B[rb]BL[824.77]
;W[rc]WL[881.838]
;B[qa]BL[822.808]
;W[sb]WL[870.417]
;B[ra]BL[818.422]
;W[mf]WL[847.793]
;B[lc]BL[727.057]C[Here's another move that I think is an error. I thought about continuing my attack on the other side by playing O14, but thought I ultimately wouldn't be able to kill anything and wouldn't get enough out of it.]
;W[md]WL[839.532]
;B[se]BL[702.736]
;W[go]WL[793.095]
;B[hp]BL[691.305]
;W[ce]WL[779.929]
;B[nf]BL[665.54]
;W[me]WL[754.22]
;B[nh]BL[653.629]
;W[oi]WL[732.28]
;B[oh]BL[649.156]
;W[mg]WL[729.969]
;B[ng]BL[647.145]C[I was kind of surprised that White decided to sacrifce those stones.]
;W[qq]WL[696.163]
;B[qr]BL[615.795]
;W[pp]WL[682.825]
;B[oq]BL[611.941]
;W[eq]WL[677.27]
;B[er]BL[607.306]
;W[dr]WL[674.264]
;B[fr]BL[587.38]
;W[fp]WL[664.213]
;B[in]BL[574.837]C[I realized immediately after playing this that White can play G4 and get a good result.]
;W[fi]WL[628.714]
;B[gp]BL[569.385]
;W[eh]WL[605.636]C[It was only about now that I saw the Black stones on the left might be in trouble.]
;B[dk]BL[561.053]
;W[cl]WL[601.087]
;B[dl]BL[557.59]
;W[dm]WL[593.196]
;B[ei]BL[544.419]
;W[fj]WL[588.846]
;B[jh]BL[540.937]C[And trying to save the stones on the left let White get a *lot* of territory on the top. I thought I was the one who had been making territory by attacking!]
;W[mh]WL[561.351]
;B[jj]BL[531.358]
;W[jl]WL[552.186]
;B[nn]BL[522.065]
;W[on]WL[519.732]
;B[nm]BL[517.129]
;W[rq]WL[501.571]
;B[li]BL[507.43]
;W[mi]WL[497.814]
;B[lk]BL[504.869]
;W[ll]WL[452.508]
;B[mk]BL[489.707]
;W[ml]WL[444.453]
;B[nl]BL[486.605]
;W[ni]WL[428.417]
;B[nk]BL[476.587]
;W[kk]WL[421.725]
;B[kj]BL[472.837]
;W[hm]WL[413.843]
;B[km]BL[400.031]
;W[kl]WL[405.327]
;B[bj]BL[395.992]
;W[bk]WL[372.485]
;B[ak]BL[391.621]
;W[cj]WL[362.195]
;B[bi]BL[382.38]
;W[bf]WL[318.381]C[It was here that I realized I didn't have two eyes with this group any longer.]
;B[bg]BL[371.655]
;W[be]WL[309.877]
;B[ah]BL[365.127]
;W[aj]WL[298.467]
;B[dj]BL[359.533]
;W[al]WL[290.436]
;B[fl]BL[355.277]
;W[gl]WL[257.475]
;B[fk]BL[338.015]
;W[gk]WL[253.138]
;B[fm]BL[327.276]
;W[fn]WL[229.316]
;B[em]BL[324.194]C[At least I've got two eyes now. I thought I was doing OK having saved all my groups, made a nice moyo on the bottom, and captured a lot of White stones in the upper right. But as I started paying more attention to counting, I realized I was probably behind, and couldn't find a good way to get to 181.]
;W[rr]WL[205.885]
;B[pr]BL[319.45]
;W[jf]WL[167.028]
;B[ig]BL[310.334]
;W[if]WL[155.118]
;B[hg]BL[302.262]
;W[hi]WL[118.277]
;B[hf]BL[299.097]
;W[he]WL[116.224]
;B[ff]BL[262.179]
;W[fe]WL[102.988]
;B[fh]BL[247.29]
;W[fg]WL[93.587]
;B[gh]BL[243.457]
;W[gm]WL[58.529]
;B[gf]BL[238.286]
;W[ge]WL[52.507]LB[ma:G][gj:D][ik:C][bm:E][rm:A][cr:F][rs:B]C[So we have
- the A-B combination
- the move at C, to be followed later by D
- the E-F combination
- and the monkey at G
How to play these so as to maximize the potential of keeping sente?
1. the lower right is the weakest group. Playing there is likely to keep sente.
2. the move at C threatens to capture 5 stones and a lot of territory. This looks like enough to swap the game result.
3. E is sente, but will crossing under at F be sente?
4. the monkey makes inroads into White's major territory. It is not sente in terms of killing but the space is big and the lone black stone may be revived.
See var.]
(;B[ds]BL[149.804]
;W[cs]WL[32.938]
;B[es]BL[146.467]
;W[cr]WL[29.818]
;B[kg]BL[142.25]
;W[pj]WL[60]OW[5]
;B[qj]BL[138.368]
;W[kn]WL[60]OW[5]
;B[lm]BL[120.522]
;W[ho]WL[60]OW[5]
;B[io]BL[116.123]
;W[jm]WL[60]OW[5]
;B[jn]BL[109.011]
;W[mm]WL[60]OW[5]
;B[ln]BL[107.36]
;W[mn]WL[60]OW[5]
;B[lo]BL[69.764]
;W[mo]WL[60]OW[5]
;B[mp]BL[67.341]
;W[no]WL[60]OW[5]
;B[pl]BL[63.855]
;W[rn]WL[60]OW[5]
;B[rm]BL[61.172]
;W[op]WL[60]OW[5]
;B[kf]BL[60]OB[5]
;W[ke]WL[60]OW[5]
(;B[na]BL[60]OB[5]C[I think I should have played N19 instead. But I think I'd still be behind.]
;W[ma]WL[60]OW[5]
(;B[oa]BL[60]OB[4]
;W[mb]WL[60]OW[5]
;B[hj]BL[60]OB[4]
;W[gi]WL[60]OW[5]
;B[ii]BL[60]OB[4]
;W[ik]WL[60]OW[5]
;B[ij]BL[60]OB[4]
;W[gj]WL[60]OW[5]
;B[eo]BL[60]OB[4]C[Oops. I only realized after my next moves that this was a mistake.]
;W[en]WL[60]OW[5]
;B[ep]BL[60]OB[4]C[I didn't see that White could play E9 here.]
;W[do]WL[60]OW[5]C[Thankfully, White didn't see it either. Not that it matters, since I'm behind anyway.]
;B[ej]BL[60]OB[4]
;W[fo]WL[60]OW[5]
;B[im]BL[60]OB[4]
;W[il]WL[60]OW[5]
;B[hn]BL[60]OB[4]
;W[gn]WL[60]OW[5]
;B[rs]BL[60]OB[4]
;W[om]WL[60]OW[5]
;B[ol]BL[60]OB[4]
;W[lp]WL[60]OW[5]
;B[ko]BL[60]OB[4]
;W[lq]WL[60]OW[5]
;B[mr]BL[60]OB[4]
;W[gq]WL[60]OW[5]C[I hadn't noticed this weakness. I knew about M4 on the other side, but concluded I didn't need to address it.]
;B[gr]BL[60]OB[4]
;W[hq]WL[60]OW[5]
;B[ip]BL[60]OB[4]
;W[hr]WL[60]OW[5]C[And now I realized I had well and truly lost. But even if I hadn't overlooked G3, I still would have been behind.])
(;B[mb]
;W[nb]
;B[la]
;W[oa]
;B[ma]
;W[ob]
;B[pa]))
(;B[ma]
;W[mb]
;B[na]
;W[lb]
;B[la]
;W[jb]
;B[kb]
;W[kc]
;B[ka]
;W[ja]
;B[pk]))
(;B[rm]
;W[rn]
;B[rs]
;W[rp]
;B[ik]
;W[jm]
;B[bm]
;W[cm]
;B[cr]
;W[cq]
;B[ds]C[Here's a decision point.]
(;W[dq]C[If White connects (lack of fighting spirit)]
;B[br]
;W[bq]
;B[ar]
;W[aq]C[Black gets many points in sente]
;B[ma]C[and the monkey]
;W[mb]
;B[na]
;W[la]
;B[oa]
;W[lb]C[in sente]
;B[gj]
;W[hj]
;B[gi]C[and two stones, probably in sente]
;W[hk]
;B[jn]C[before taking gote here
This is the ideal scenario.
Black is ahead by 10 points or so.])
(;W[br]C[White is better off playing the ko]
;B[dq]C[This ko looks really big.
]
;W[mj]C[major threat]
;B[lj]
;W[dr]C[Black doesn't have a lot of ko threats, because he used most of his sente
I won't discuss the ko any further but I think White needs to play it.])))