(;GM[1]FF[4]SZ[19]AP[SmartGo:3.1.2]CA[shift_jis]
GN[selfplay24_annotated]
PW[AlphaGo]
PB[AlphaGo]
EV[AlphaGo selfplay]RO[24]
KM[7.5]
RE[W+R]
RU[Chinese]MU[1]
C[Commentary by Michael Redmond 9P; edited by Chris Garlock];B[qd];W[dp]
;B[pq];W[dc];B[nd];W[po];B[qo]
C[In modern Go Black A has become even more popular than before, while pincers at B or C were fairly common before AlphaGo. Go playing AIs seem to attach more value to taking the corner territory than was normal before. ]
LB[qo:A][qm:B][pl:C];W[qn];B[qp];W[pn];B[nq];W[pp];B[qq];W[pj];B[ce]
C[AlphaGo attaches a high value to Black pressing at A next. ]LB[ed:A];W[fd]
C[White A has become the most common move against Black B. ]LB[fd:A][ce:B]
;B[di]LB[di:A][ci:B]
C[Black's high extension at A has potential to expand into the center, but is unstable and potentially subject to attacks from White when compared to the low extension at B. Black A is an example of surrounding an area with acombination of stones on the third and fourth lines. This has always been considered a good idea when playing in an area that is controlled by friendly stones, but humans before AG would have played the low extension at B when the left side is controlled by White, as in this board position. ]
;W[fq]TR[nq][pq:qq]LB[ck:A][lc:B]
C[White 18 is a move that I would not have considered, as the marked Black group is solid, and this reduces the value of the lower side. My first idea would be to play White A, and next I might think of the extension at B. Both of these points seem to be equally big, so maybe AG is calling them miai?]
;B[cn];W[lc];B[qh]LB[hc:A][cp:B]
C[Black 21 reinforces Black in the upper right while reducing White's potential on the right. Other important points that catch my eye are Black A, which has some attacking potential against White's UL corner, and Black B, which is just a favorite move for AG and most pros now. ]
;W[dk];B[cp];W[cq];B[bq]
(;W[br]
C[White's double hane in the corner is a move that strongly defends the corner territory and refuses to give Black eye shape. The normal move was a wedge on the third line (see var). ]
(;B[bo]
C[Looking at the cutting points in White's shape, one might be tempted to cut with Black, but that would have been a bad idea (see var). ]
;W[aq];B[do];W[bp]
C[White has refused to give Black a living shape, and in return Black has played some forcing moves against White's corner with tempo, including A which was played later. I would call this about even. ]
LB[ep:A];B[hc]
(;W[pc]
C[White 32 will have the effect of making a base for the marked stone. My first idea for White was to invade on the left, but I could not find a good variation for White (see var). ]
TR[lc];B[pd];W[nc];B[oc];W[ob];B[od];W[mb];B[pb];W[jc]
C[White can usually find a good time to force with A if Black triues to attack on the upper side, so for practical purposes, the White group is settled now. ]
LB[pa:A];B[ep];W[dq];B[pk];W[qk];B[ql]
(;W[rl]
C[White's hane underneath is a tesuji, and is better shape than simply cutting (see var). ]
;B[qj];W[rk];B[oj];W[pi];B[qi];W[ok];B[pl];W[oi];B[ol];W[nj];B[nl];W[mp]
(;B[mk]
C[Pushing through on the fourth line was an option, but Black must be careful of playing too many moves on the lower side and leaving the center weak (see var). ]
;W[np];B[mq];W[lp];B[li];W[pg];B[qg];W[mg]
(;B[kg]
C[The proverb says to attack with the keima (knight shape). However, Black's thin shape in the center became an issue later in the game, so I will suggest that Black could have player a more solid sequence (see var). ]
;W[qf];B[ph];W[oh];B[pf];W[og];B[rf];W[lh]
(;B[ki]
C[White had an idea to make two eyes in the center, so Black resists by pulling back (see var). ]
;W[kh];B[jh];W[jg];B[ih];W[ig];B[hg];W[kf];B[jf]
C[Black 83 creates some forcing moves to accelerate Black's connecting to the marked stone. ]
TR[hc];W[if];B[hf];W[ie];B[he];W[fk]LB[hh:A][ji:B]TR[hc]
C[Black pushed White around in the center to make a big wall and managed to connect to the marked stone in the process, so was this a success for Black? A wall is not always thickness, and Black's wall has weaknesses at A and B. Both sides have potential attacks in this position, as we will see. ]
;B[rn];W[rm];B[ro];W[qm];B[kn];W[mm];B[kl];W[hh];B[jp];W[lq]LB[ln:A][jq:B][rj:C]
C[Just to check the status of White's group in the lower right, White has potential eyes at A and B that will come with tempo, and can make a second eye at C. ]
;B[ij];W[gh];B[ff];W[eh]LB[cn:A][ff:B][eh:C][dc:D][lp:E]
C[With White 102, it becomes difficult for Black to hold on to the left side area. Black's group in the center is in fairly good shape now, but Black has weak groups at A and B. White also has weak groups at C and D. White's group at E is safe for now, but as the fight heats up, White will have to deal with threats against it. ]
;B[cc];W[cb];B[bc];W[gn]
C[White starts to attack Black on the left, while eyeing Black's group in the center also. ]
;B[hl]
C[Black can later deal with the left side by playing at A, as we will see in the game. For now, Black reinforces the center and is preparing a lethal attack on White's group in the lower left. ]
LB[ck:A];W[gl];B[hm];W[gm];B[hp]
(;W[ko]TR[hl:hm][hp]
C[The three marked moves were threatening White's group (see var).];B[ln]
;W[jo];B[io];W[jn];B[jm];W[in];B[hn];W[go]LB[ko:A][go:B]TR[hl:hm][hp]
C[The sequence from White A was played to make this peep at B forcing. This sequence also demonstrates how the three marked stones are enabling Black to play strongly after White A and put the White group in danger. ]
;B[ho];W[mn];B[lo];W[jq]
C[White ];B[iq];W[mr];B[nr];W[kr]LB[om:A][rj:B]
C[White now has an eye on the lower side, and can make a second eye by playing at A or B.]
;B[ck];W[cj];B[bj]
(;W[ci]
C[At first I thought this was a very weak move for White. Why not just cut on the second line to capture a stone, putting much more pressure on Black's group? I will attempt to answer that question in the var. ]
;B[bi];W[ch];B[cl];W[dd]LB[dd:C][ci:A][bk:B]
C[At White 132 (A) I showed a var in which Black sacrificed the left side to capture the UL corner and win. The virtue of White pushing through at A was that the left side became too big for Black to sac, and White got sente to play this important move at C. ]
;B[de];W[gb];B[ee];W[ns];B[or];W[id]LB[hd:A][hb:B]
C[By creating a cutting point at A, White has secured a connection at B. ]
;B[dj];W[dh];B[ek];W[bf];B[be];W[bh];B[ed];W[ec];B[bb]LB[bb:A][ef:B]
C[Black secures an eye in the corner, with anotherpotential eye in the vicinity of B. ]
;W[fe];B[eg];W[hd]LB[hd:A][co:B]
C[White connects at A, and most of the fighting is over, but there is still a ko at B with which White can try to harass the Black group. ]
;B[kp];W[kq];B[im]TR[in:jn][jo:ko]LB[rj:B][ls:A][on:C]
C[After Black captures the marked stones, White already has one eye at A, and a potential eye at B, but has lost the ability to make an eye in the vicinity of C. Therefore White needs to add a stone to this group. ]
;W[mi]LB[ml:A][on:B]
C[White threatens a squeeze starting from A that will create an eye at B. ]
;B[ml];W[rj];B[ri];W[gr]
C[White surrounds some extra territory from the corner while saving the White group. ]
;B[ir];W[js]LB[is:A][sj:B]
C[The connection at A and the second eye at B are miai. ];B[db];W[ai];B[ak]
;W[eb];B[ca];W[co]TR[bo][do]
C[The game is very close, making this ko difficult for Black. Black's group is under attack, but Black cannot afford to sac either of the marked stones. ]
;B[jr];W[ks];B[cp];W[pa];B[gp]
C[Black takes this opportunity to counter-attack. White's group does not have two eyes that can be easily found. ]
TR[dh:eh][gh][fk];W[fp];B[gd];W[fc];B[fo];W[fg];B[os];W[is];B[gf];W[el];B[dl]
;W[em]
C[White makes an eye at A while making the ko at B even more threatening that it was before. ]
LB[fl:A][co:B];B[bm]
C[Black lives. ];W[ao]LB[co:A][gj:B]
C[There is still trouble for Black if White captures at A. This seems to balance the fact that White is not alive until White adds a stone at B. I would expect Black to defend at A, after which White would defend at B. ]
;B[qb];W[gj]LB[co:A][gj:B]
C[While I thought the sequence would be Black A, White B. AG does it backwards. I find it strange that White did not attack at A first, but maybe AG already knows that White is winning, and doesn't care whether it is a half point or not.]
;B[co];W[qa];B[hk];W[gk];B[ra];W[oa];B[rb];W[md];B[ea]LB[ea:A][fa:B][gc:C]
C[The threat with Black A is that if White B, Black can connect at C. ];W[ge]
;B[me];W[le];B[hr];W[hs];B[ga]
(;W[an]LB[an:A][ga:B]
C[White plays away once at A, which is threatening Black's group on the left. That move Black B looks strange, can't White throw in and capture it (see var). ]
;B[dm];W[hb];B[fa];W[ha];B[of];W[mf];B[mo];W[no];B[eq];W[er];B[eo];W[gq]
;B[mj]LB[mj:A][lj:B]
C[Black A prevented a big move for White at B. White failed to play at B earlier, which is stupid by human standards, but with AG it just indicates that White is going to win anyway. ]
;W[dg];B[ef];W[lm];B[cf];W[af];B[hi];W[cg];B[fi];W[gi];B[ei];W[fh];B[sj]
;W[cd];B[bd];W[hq];B[ip];W[ll];B[lk];W[ms];B[ne];W[op];B[dr];W[ds];B[om]
;W[on];B[fs];W[gs];B[es];W[cr];B[fn];W[fm];B[nk];W[oj];B[lg];W[mh];B[sm]
;W[am];B[al];W[oq];B[qr];W[hj];B[ii];W[fb];B[da];W[nf]
C[The game will continue with the sequence Black A-White D, and then only dame points are left. Apart from the more obvious connections, note that Black must add a stone at E. 
White wins by half a point. ]
LB[fj:A][ae:B][ad:C][en:D][kk:E])
(;W[fa];B[fb];W[ha];B[gc];W[fa];B[cd]
C[A dangerous ko. ]))
(;W[bk];B[cl];W[bi];B[dj];W[ci];B[dh];W[eg];B[ee];W[bl];B[bh];W[ch];B[cg]
;W[aj];B[dg];W[dl];B[id];W[je];B[kp];W[kq];B[im];W[ns];B[or];W[gr];B[ir]
;W[rj];B[ri];W[js];B[hb]LB[bk:A][bi:B][dh:C][bl:D][kp:E][hb:F]
C[Cutting at A and capturing at B is White's strongest move on the left. Black has little choice but to push through at C, and after White D the Black group is in trouble. However, I was suprised to find that Black can just sac the left side. Black plays a forcing sequence at E and captures the UL corner with F. Black has a small lead. ]
))
(;W[bk];B[jq];W[ln];B[ko];W[kr];B[jr];W[mr];B[nr];W[rj];B[ri];W[sj];B[lo]
;W[mo];B[on];W[nn];B[oo];W[op];B[nm];W[ll];B[lk];W[km];B[jl];W[jm];B[hn]
TR[hl:hm][hp]
C[If White plays away at A, the three marked moves have reinforced Black's connection in the center to make this attack possible. Without these extra stones White would have been able to make an eye with tempo in the vicinity of B, but with the marked stones White has no way to save this group.  ]
LB[bk:A][mo:B]))
(;B[kh];W[lj];B[mj];W[mi];B[ki];W[nk];B[ll];W[cg]
C[White lives with sente, and the stone at A still has some potential to escape. This is good for White. ]
LB[lj:A]))
(;B[mh];W[nh];B[lg];W[mf];B[lf];W[me];B[kl]LB[mh:A][kl:B][cg:C]
C[After forcing White to connect dame points with the sequence from A, Black returns to B to make a strong position in the center. White will switch to the left, maybe with C, and the game is about even. ]
))
(;B[np];W[no];B[mo];W[mn];B[lo];W[nn];B[ll];W[ln];B[ko];W[kn];B[jo];W[jn]
;B[io];W[pg];B[qg];W[mk];B[ml];W[kk]
C[Black's group in the center is in danger. ]))
(;W[pl];B[ok];W[qj];B[rl];W[qm];B[ol];W[pm];B[ri];W[rm];B[oj]
C[Black has potential to squeeze, and White is not yet alive. This looks not bad for Black. ]
))
(;W[cg];B[dg];W[dh];B[ch];W[eh];B[bg];W[ci];B[cf];W[bh];B[cj];W[cg];B[ed]
;W[ec];B[ch]LB[or:A][qc:B][bi:C][dj:D]
C[When White invades on the left, this ko fight must be considered first, in that both sides have played the strongest moves. White has ko threats at A or B, but in either case Black will finish the ko at C and have an advantage. White might just connect at C to continue the ko after Black D. This fight looks difficult for White. ]
))
(;B[dq];W[cr];B[ep];W[do];B[eq];W[co];B[fp];W[dn];B[ip];W[cg]TR[cn:cp][dn][bq:br]
LB[dq:A]
C[When Black cuts at A to force this trade, the result is bad for Black locally, and in this position when the left side was more important than the lower side, Black's direction of play was not good either. Tewari analysis would suggest that the marked stones could be viewed as three terrible moves by Black being answered by relatively good moves by White. ]
))
(;W[co];B[bp];W[do];B[bo];W[cr];B[dn];W[cg]LB[co:A][dn:B][cg:C]
C[When White wedges at A, the basic joseki to Black B will follow. White invades at C, and the fight will continue. ]
))

