(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]RU[Japanese]SZ[19]KM[0.50]PW[Soren Jaffe REVIEW]PB[David Sun REVIEW]WR[四段]BR[三段]DT[2017-06-24]EV[Toledo Go Club Tournament]RO[3]C[This is a third round match between Soren Jaffe (W) AGA 4d vs. David Sun 3d of the Toledo Go Club Tournament. Commentary by Soren Jaffe.]RE[白胜黑];B[pd];W[dd]C[I played a new-ish, AlphaGo inspired style during this match.];B[pq]C[AlphaGo will take local losses in order to regain sente and maintain momentum and fluidity of the match.];W[dq];B[qk]C[Black plays the low Chinese opening. A very popular opening in this era of Go.];W[nc];B[pf];W[mp]C[White is trying to overconcentrate black onto the right side of the stage.];B[po](;W[oe]C[Another move made popular by AlphaGo that is against normal Go philosphy.](;B[pe]TR[qc]C[It is a bad move locally, as the 3-3 spot (▲) is no longer an option. P15 does allow for a bit more center infleunce while retaining sente.](;W[dn]C[A shimari made popular by AlphaGo. It hopes to gain immense power in the center.];B[lc]C[Black attacks the upper right group.];W[jp]C[However, white treats them lightly and tenukis.];B[fc](;W[df]C[White plays high despite the lower left shimari, because white doesn't care about side territory. White wants infleunce in the center.];B[id];W[le]LB[jc:1][kc:2]C[White plays lightly, aiming at disconnection at either 1 or 2.];B[md]C[Black takes the bait.];W[kc]C[White plays the shape point, black cannot refute strongly](;B[kb]C[Black has to crawl. See variations as to why black cannot cut.];W[jc];B[ic];W[jb];B[mb];W[ka];B[lb];W[je];B[hf](;W[pc]C[White plays a tricky move.];B[qc];W[me];B[nd];W[od]TR[pc][qc]C[This is the reason behind white's q17/ r17 exchange.];B[ne]C[White is heavy however. Hard for white.](;W[qb];B[of];W[oc];B[mg];W[rc];B[qd];W[rd];B[re];W[ob];B[jg]C[Corner is white's, but black takes the outside. However, the white group has a lot of aji..];W[pj]TR[nf]C[White is aiming at ▲];B[oi]C[Black tries to play strongly in the area, however...];W[ld];B[mc];W[nf];B[mf];W[ma]C[White can connect under!](;B[eq]C[So in hindsight, B P11 should just be O14. Now black is at a disadvantage and must catch up.];W[dp];B[hp];W[pn]TR[pj]C[White's attachment is using the aji of W▲](;B[ol]C[Black tries to respond aggressively.];W[oo](;B[qo];W[gm]C[White is attack black's lower group in order to build the left side.](;B[hn];W[om];B[nl];W[op];B[oq];W[nq];B[lq]C[Black tries to attack, however...];W[nr]LB[pp:2][jq:1]C[1 and 2 are miai for white to live.](;B[rq]C[In the game, black protected the corner stones, however...];W[qr];B[qq];W[rn];B[pr];W[jq]C[Black's bottom left group is baseless, and white is alive on the bottom.];B[ko];W[jo];B[hm];W[gl]TR[nn]C[See ▲ for a variation](;B[lp]C[Black tries to fight, however..];W[lo]C[White has this nice hane.];B[ln];W[mo];B[kn];W[kp];B[ch]C[Black realizes now he is behind.];W[cj];B[eh];W[ec];B[cc]C[Black is playing strongly.];W[cg];B[ci];W[fb];B[be];W[bf];B[ce];W[eg]C[Key move, because it connects all of white's stones in one move.];B[db];W[fd]C[Key point in both group's shape.];B[gc];W[eb];B[bb];W[gd];B[hd];W[hl];B[il];W[fh];B[ck];W[ig]C[Black is struggling to stay alive and connected.];B[if];W[jf];B[gh]C[Nice move, however..];W[ei]C[One of black's groups suffer.];B[ih];W[kg](;B[dj];W[jh]C[Weird tenuki by black. this gives white immense power in the local fights.];B[hh];W[ik]C[Black is getting cut up mercilessly.];B[ji];W[ki];B[jj];W[im];B[jl];W[in];B[io];W[jn];B[em];W[en];B[fn];W[fm];B[dm];W[cm];B[cl];W[cn];B[fo];W[hr];B[gq];W[jk];B[kl];W[kk];B[lk];W[kj]LB[hf:1][dj:2][hp:3]C[At this point, black has groups 1-3 that are not alive, a side that can be reduced, and two small corners. White is clearly ahead at this point. Main commentary and review will end now. Closing comments at Move 168.];B[hj];W[ek];B[fg];W[dh];B[ff];W[de];B[gi];W[bj];B[bk];W[bh];B[bi];W[bm];B[ej];W[fj];B[fi];W[di];B[aj];W[dk];B[cj];W[fk]TR[ah]C[Even if black ataris at ▲](;B[gb];W[ah](;B[cf];W[al];B[af];W[bg]C[At this point, white wins the semeai, so black resigns. After the tesuji to let white connect at the top in the opening, black was struggling to reduce white's big potential while staying alive.])(;B[al]C[Even if black tries to make a ko...];W[bl];B[cf];W[am];B[af];W[bg];B[eh];W[dg];B[ee];W[ed];B[ge];W[ai];B[fe];W[ak]C[A four step ko for black, no way to win the ko at this point. Black has lost]))(;B[ah];W[hb]C[White can just give up the stone, the black group in the middle is dead.]))(;B[jh];W[bj]C[Black didn't like this result. Clearly white is ahead on this board.]))(;B[nn]TR[om][pn][rn]C[What if black peeps? no good response for white (assuming white wants to save the marked ▲ stones](;W[on]C[If white connects];B[lp];W[lo];B[kn]LB[mo:1][kp:2]C[white's hane at m5 doesn't work because of miai between 1 and 2. However white can avoid this.])(;W[mn]C[The key move might be this, however];B[nm];W[on];B[lp];W[lo];B[kn]C[doesn't quite work.])))(;B[jq]C[Because black invested in m3, he should connect.];W[pp];B[qp];W[qq];B[rq];W[qr];B[rr];W[pr];B[qn]C[Black's bottom group is now settled. Good result for black.]))(;B[on];W[in]C[Black cannot ignore G7.]))(;B[on]C[Cannot cut...];W[qn];B[qo];W[om];B[nn];W[nm](;B[pm];W[mn];B[no];W[np];B[op];W[mo];B[oo];W[pl];B[qm];W[ql];B[rn];W[pk]C[Disaster for black.])(;B[mn];W[pl];B[pk];W[ql]C[Difficult fight for black.])))(;B[qn];W[oo];B[pm];W[on];B[qo];W[nl]TR[hp][eq]C[White is aiming to attack B▲])(;B[oo];W[ol];B[qn];W[lm]C[White's play is graceful.])(;B[pk];W[oo];B[qo];W[nm]C[Black feels unhappy.]))(;B[na];W[nb];B[la];W[ma]C[Black cannot seperate due to a snapback.]))(;W[nf]C[directly cutting black off..];B[of];W[oc];B[pb]C[White loses by one liberty])(;W[of];B[nf];W[og];B[pb]C[Painful for white.]))(;W[kh]C[White should just jump out, and leave the upper right for later.]))(;B[kd];W[ld](;B[jc];W[mc];B[kb];W[lb];B[kc];W[lf]C[White is successful.])(;B[mc];W[jd](;B[jc];W[ke];B[kb];W[nm]TR[qc]C[White has now created a potential flower ko for later, and now that the outside is not important, the 3-3 (▲) is now an option])(;B[ke];W[je];B[kf];W[jc]C[White gains here.])))(;B[ld];W[kd];B[ke];W[je];B[kf];W[jd]C[Black's shape is a mess.]))(;W[cf];B[dg]C[Later on, black can reduce white's moyo easily with a shoulder hit.]))(;W[qc]C[If white tries the 3-3...];B[pc];W[pb];B[ob];W[qb];B[oc];W[re];B[rf];W[qe];B[qf]TR[oe][pe]C[We can see the marked exchange for white is a terrible exchange.]))(;B[co]C[If black ignores...];W[pe];B[qe]TR[qd][qf]C[Leaves deadly cutting points (▲). Hard for black to ignore the white peep.]))(;W[ne]C[White's regular jump seems normal...];B[co]C[Black can approach the last empty corner though. White's plan fails.]))