(;GM[1]FF[4]SZ[19]AP[SmartGo:3.1.3]CA[shift_jis]
PW[AlphaGo]
PB[AlphaGo]
EV[AlphaGo selfplay]RO[18]
KM[7.5]
RE[W+R]
RU[Chinese]MU[1]MU[0];B[pd];W[dd];B[qp];W[dp];B[fq];W[cn];B[op]LB[kq:A][lq:B]
C[ AlphaGo played this shimari in game 7 of this set, so it appears for a second time here. This version of AG also likes the mini Chinese openings, both A and B (see games 01 and 12 for examples with commentary). ]
;W[qf]LB[jp:A][qj:B]
C[While AG played this kakari both times in this board position, I would also consider a pincer somewhere around A, or entering the right side at B. ]
;B[nc]LB[nc:A][pi:B]
C[AlphaGo almost always answers at A, but many human pros would want to pincer at B with this move. As AG gets more advanced, it's apparent bias towards taking territory in the opening gets stronger.]
;W[np]LB[pj:A][qj:B]
C[White's attachment against Black's shimari intuitively looks like an overplay, and it was a shocking move when I first saw it. However, this game and game 7 of this set have given us reason to think that it might actually be a feasible move, and some human pros are trying it in tournament games. Before AlphaGo, I would not have hesitated to play an extension at A or B with White. ]
(;B[no]
C[This hane is the most active move for Black. In game 7, AG played a sagari on the 3rd line (see var). ]
;W[oq]
(;B[oo]
C[Black's connection was a patient move. Black could also have closed White into the corner (see var). ]
;W[pq];B[mp];W[nq]
(;B[qq]
C[If Black covers from outside with this move, White will be able to live in the corner with sente (see var). ]
;W[mq]
(;B[qi]
C[Black combines a pincer with a big side extension, obviously an important move. However, this allowed White to take the initiative on the lower side, which is also important. I suggest Black should have extended once (see var). ]
;W[lp];B[mo];W[iq]LB[iq:A]
C[White attacks with A, a big pincer-extension, and now the lower side has potential to expand and become a big area. Black has only the right side, which is big, but also is too wide open to be called territory yet. White has a slight advantage. ]
(;B[cc]
C[Before AlphaGo this invasion to the 3-3 point would have been called bad, but now we are seeing it played by human pros as well as machines. I still have a tendency to want to play an approach move from the side (see var). ]
;W[cd];B[dc];W[fc];B[ec];W[ed];B[fb];W[gc];B[gb];W[hc];B[qd]LB[qd:A][qf:B]
C[Black A takes away White's base to attack the stone at B. ];W[qj]
C[In AlphaGo's games, it is not uncommon to discover than an unexpected group comes under attack. What we might think of as outside influence can quickly turn into a weak group. This might seem to happen suddenly, but I would say that the eye space of groups is a vital part of AlphaGo's calculations, and thus advance preparations are made for these attacks.  In this case Black dominates the right side, but White 34 and the following moves are not just trying to live inside Black's area, they also focus on the fact that Black's wall, the LR group, is not completely alive when one looks at the corner shape. ]
;B[pj];W[qn]
C[White threatens to cut with A.]LB[pp:A]
(;B[qo]
C[Black's bamboo joint is the safe move, while I would want to clasp a stone on the side (see var). ]
;W[rj]TR[qf]
C[White will make use of the marked stone as a sacrifice to make shape on the lower side. ]
;B[ri];W[pi];B[rg];W[ph];B[qg];W[ql]TR[qf][ph:pi]
C[White is prepared to sacrifice the marked stones in this fight. ];B[pk]
;W[pg]
(;B[rf];W[om]
C[White's keima is a light shape that moves out more quickly than pushing at A. ]
LB[pl:A];B[nk];W[nl];B[mk];W[ml]
(;B[lk]TR[qj:rj]
C[The marked stones are not fully connected, but it is not worthwhile for Black to go after them (see var). ]
;W[ll];B[ol];W[pl];B[ok];W[nm];B[kk];W[kl];B[jk];W[jl]
(;B[jf]TR[qj:rj]
C[As before, White's connection to the marked 2 stones is not perfect, but if Black goes after them the group in the corner will be endangered (see var). ]
;W[jh]
(;B[hk]
C[Black jumps out in the center, leaving the right side for now, and putting more emphasis on reducing White's potential on the left. Black could have surrounded the right side with this move, but then White would have closed off the center (see var). ]
;W[lh];B[ih];W[lf];B[jd];W[rm]TR[qj:rj]LB[rm:A]
C[White A makes a secure connection for the marked stones, and strengthens the White group as a whole. White threatens the eyespace of the Black group in the corner. ]
;B[lo];W[kp]
(;B[ro]LB[ro:A]
C[If this was a tsumego problem, the correct answer for Black would be a kosumi in the corner (see var).]
;W[md]TR[jd][jf]
C[White moves into the upper side, starting to cut off the marked stones, and thus preparing to cut Black in the center. ]
(;B[nh]TR[pg:pi]
C[Black goes after the marked stones, thus strengthening Black's group in the center. The variation shows how White might have been planning to attack in the center. ]
(;W[nd]TR[nh]
C[White switches to the upper side to set up a trade. The variation shows what might happen if White answers Black's marked move directly. ]
(;B[nf]TR[pg:pi]
C[Black is in the process of capturing the marked stones. Black's main goal in this fight seems to be to create a strong position in the center, which will serve as a base for Black to reduce White's potential on the left. Black is just ignoring the upper side and adding stones to the center. The var shows what might happen if Black plays on the side instead. ]
;W[oc];B[le];W[il];B[ld];W[mc];B[ii]TR[lf][pg:pi][jh][lh]
C[Black has captured the marked stones to create a strong position in the center and make a territory of more than 40 points, while White has erased Black's area on the top. Locally, this looks like a slight gain for Black. ]
;W[oe];B[lb];W[lc];B[kc];W[mb];B[pb];W[pc];B[qc];W[ob];B[of];W[qr]
C[White starts the ko in the LR corner. This ko was waiting to happen for the last 20 moves, but the fighting in the upper right was too urgent for White to play away until now. ]
;B[rr];W[pf]
(;B[me]LB[pf:A][me:B][rs:C]
C[Both White A and Black's answer at B are moves that might seem strange in the local position, but can be explained when one realizes that the real issue here is the number of ko threats for the ko starting with a White play at C (see var). Black B reduces the number of ko threats for White. ]
(;W[rs];B[pr];W[ps];B[qs];W[qb]
(;B[rb]LB[qb:A]
C[White A threatened to save the marked group with sente, so it was a big ko threat (see var). ]
TR[pf:ph];W[qr];B[pn];W[pm];B[qs];W[re];B[qe];W[qr];B[or];W[nr];B[qs];W[qh]
(;B[rh];W[qr];B[qa];W[os];B[jb];W[dq]
C[Drawing a boundary on the marked points for White's territory in the lower right, White has a total of almost 85 points when including the LL corner territory. Black has about 95 points, giving Black a temporary lead in territory, but White can catch up on the left or lower sides, and White has a small lead. Black would like to attack White in the upper left, but this is not easy because the peep at A is not forcing in this board position, as the left and lower sides are bigger than capturing 3 White stones on the upper side. ]
TR[im:ip][ir:is]LB[fe:A];B[hq];W[ip];B[gn]
C[When Black reduces the lower side like this, White's plan will be to surround territory on the left while attacking. ]
;W[ik];B[ij];W[hl];B[hp];W[gr];B[em];W[gk];B[io];W[dl];B[hr];W[fr];B[gq]
;W[eq];B[eo];W[in];B[fk];W[ek];B[jo];W[ko];B[fl];W[fj];B[jn];W[kn];B[bc]
(;W[cg]
C[Black's group is alive (see var).];B[be];W[bd];B[cf];W[df];B[bg];W[hn]
;B[dm];W[cm]TR[jn:jo][io]
(;B[ch]
C[Black can live locally on the lower side, but will be forced to sacrifice 3 stones.]
;W[dg]
(;B[gj]
C[Black had a choice of cutting on the right or the left (see var). As the Go proverb says, White will capture the cutting stone. ]
;W[hj];B[ej];W[gi];B[dk];W[ig];B[hg];W[cl];B[el];W[cj];B[bi];W[if];B[ie]
;W[hf];B[jg];W[dj];B[do];W[co];B[ei];W[dh];B[ck];W[bk];B[di];W[ek];B[ci]
(;W[he]
C[Black can make life by playing at A, so does not need to actually connect to the left side. White B is an important move that saves White's group in the upper left from being attacked severely (see var). ]
LB[gm:A][he:B];B[gg];W[ff];B[ho];W[dk]LB[ho:A][dk:B]
(;B[fi]
C[Black challenges White to a ko instead of just living on the lower side. In the end, this did not make much difference in the result (see var). ]
;W[hh];B[ad];W[gm];B[gj];W[ce];B[bf];W[fn];B[fo];W[fj];B[go];W[fm];B[gj]
;W[id];B[je];W[fj];B[cq];W[er];B[gj];W[hi];B[jj];W[fj];B[cp];W[cr];B[gj]
;W[fh];B[eh];W[fg];B[gl];W[fj];B[jr];W[kr];B[gj];W[hk];B[fj]
(;W[ir];B[is];W[jq];B[hb];W[ic];B[sj];W[js];B[sk];W[rl];B[sr];W[rn];B[gs]
;W[fs];B[hs];W[ib];B[ia];W[jm];B[gf];W[ge];B[pp];W[on];B[aj];W[ak]
(;B[ep]TR[si]
C[The marked point was slightly larger than the other remaining points, so Black should have taken that point, but it would not have changed the outcome of the game (see var). ]
;W[bj];B[sl];W[sm]
C[The game ends with Black resigning. Black must connect at A, after which White will capture at B. White will win by a quarter of a stone, or 1 and a half points in Japanese counting. ]
LB[si:A])
(;B[eg];W[ef];B[si];W[bj];B[ai];W[sl];B[ep]
C[White wins by 0.25 stones, or a half point in Japanese counting. ]))
(;W[hb];B[jq];W[jp];B[kq];W[ir];B[is];W[lq];B[js];W[gs];B[hs];W[lr];B[sj]
C[B+0.75 (0.5)]))
(;B[jr];W[kr];B[ir];W[kq];B[gm];W[ac];B[ab];W[ad];B[ah];W[ce];B[bf];W[hb]
;B[ba];W[hh];B[fh];W[id];B[je];W[fg];B[gh];W[hi];B[jj];W[fi];B[eh];W[si]
;B[sh];W[sj];B[rd];W[ic]
C[When Black simply lives with the sequence to A, White will win by 1.5 points, about the same as in the game.]
LB[gm:A]))
(;W[dk];B[fi];W[gj];B[gh];W[gg];B[hh];W[ce];B[bf];W[fg];B[he];W[gf];B[fe]
;W[ee];B[ge];W[ff];B[gm];W[ho];B[go];W[fd];B[jr]LB[gh:A][fd:B]
C[This diagram is an example of how White's group in the upper left might be squeezed. When Black plays at A, the upper left is bigger than capturing Black's group on the lower side. White is forced to live with just 2 points, and then to add one more stone at B to save 3 stones. In this variation, Black is going to win by about 10 points before komi. ]
))
(;B[ej];W[dj];B[gj];W[ei];B[gl];W[ad]LB[ej:A][ad:B]
C[If Black starts with the cut at A, White will capture this stone, allowing Black to connect in the center. White B kills Black on the left, and White will win. ]
))
(;B[gm];W[ho];B[go];W[ch]
C[White captures 3 Black stones with sente, and White has a lead in territory now. ]
))
(;W[hn];B[gm];W[ho];B[go]
C[Black is alive.]))
(;B[os];W[rh];B[cg];W[bc];B[bb];W[be];B[ac];W[ch]))
(;B[os];W[rb];B[re];W[pe];B[rc];W[dq]LB[qb:A]TR[pf:ph]
C[If Black finishes the ko when White cuts at A, White can squeeze Black on the right and save the marked group with sente. In territory, Black has a lead of about 15 points before komi, but White will be able to catch up with an attack on the lower side. ]
))
(;W[bc];B[bb];W[di];B[pr];W[dq]))
(;B[pe];W[me];B[mf];W[rs];B[pr];W[ps];B[qs];W[ke];B[kd];W[qr]LB[pe:A][kf:B][ni:C]
C[If Black cuts at A, White will start the ko in the LR corner. White has a large number of ko threats here, starting with White B and then C, and White will be able to easily win the ko. ]
))
(;B[mc];W[lc];B[od];W[ii];B[hh];W[jg];B[if];W[ig];B[hg];W[hf]LB[mc:A][hf:B][hi:C][jc:D]
C[If Black plays at A on the side, White will continue with the sequence up to B, cutting Black in the center. Next White can push at C or attach at D to attack one or the other of Black's groups. ]
))
(;W[ng];B[mg];W[mh];B[nf];W[og];B[mf];W[kf];B[nd];W[ni];B[ji]LB[ng:A][ji:B]
C[If White plays at A, Black can destroy most of White's eye space with the following sequence. Black's final move at B reinforces Black in the center, and this variation is not good for White. ]
))
(;B[nd];W[ii];B[hh];W[jg];B[if];W[hi];B[ji];W[gi];B[gf];W[ki];B[jj];W[il]
;B[hj];W[ne]LB[nd:A][ii:B][ne:C]
C[Black A looks like a natural response to White's shoulder hit, so I made this diagram. White can hane at B to cut Black off in the center. This sequence also makes some eyespace for the White group, and after White C, this group looks just about alive. Black's group in the center is not settled yet. ]
))
(;B[rr];W[pr];B[sq];W[qr];B[qs];W[ro];B[rp];W[so];B[sp]LB[rr:A]
C[Black A is the tesuji seen in tsumego that gives Black a life without ko. However, this is too painful for Black when White can gain territory and make a living shape on the right side while forcing Black to live with just two eyes. ]
))
(;B[kh];W[ki];B[lh];W[ik];B[ij];W[hj]LB[kh:A][ik:B][kd:C]
C[If Black answers at A to surround the right side, White then plays B to close off the center and expand White's potential on the left. This is good for White. ]
))
(;B[qk];W[rk];B[pm];W[pn];B[rl];W[qm];B[sj];W[ro]TR[jl:kl]
C[Black's group in the corner is not alive, and now the marked White group is forming a wall, so it will be difficult for Black to escape. ]
))
(;B[pl];W[pm];B[qk];W[rk];B[rl];W[rm];B[qm];W[oj];B[ok];W[ql]LB[pl:A][sl:B][lk:C]
C[If Black pushes through at A, Black can make a ko to capture White's stones on the side. However, this ko is relatively light for White, and difficult for Black. If White wins the ko, Black's group in the corner will not be fully alive. If Black now plays at B, White will not immediately continue the ko, but can hane at C and have potential to squeeze from the center. This is good for White. ]
))
(;B[pl];W[rm];B[rf];W[pm];B[nl];W[on];B[mm];W[lh]))
(;B[qk];W[pp];B[po];W[qo];B[lq];W[lr];B[kq];W[kr];B[rp];W[pl]LB[qk:A][rp:B][pl:C]
C[If Black plays at A, White will push through to cut. Black B does not make a life yet, but gives Black an advantage in an immediate semeai. After White C, I cannot see how Black can continue to capture the White group, so maybe this is not working for Black. ]
))
(;B[fc];W[cf];B[id];W[qd];B[qc];W[rc];B[qe];W[rd];B[pe];W[re];B[qb];W[rg]
;B[pg]LB[fc:A][qd:B][pg:C]
C[With Black, I would have played the kakari at A. If White then plays B to live in the upper right, Black can enclose White with C to start making a moyo in the center. ]
))
(;B[lp];W[kq];B[qi]TR[fq]LB[lp:A][kq:B]
C[The exchange of A for B has reduced the value of White's next move on the lower side, and this makes it difficult for White to effectively attack the marked stone. This is better for Black when compared to the actual game, and the overall position is about even. ]
))
(;B[mq];W[pp];B[po];W[qq];B[ro];W[rp];B[qo];W[qi]LB[ip:A][mo:B]
C[This diagram ends with the same shape as a previous diagram. White has potential to invade somewhere around A and set up a cut at B. Since Black's wall has this weakness, I like this for White. ]
))
(;B[mp];W[nq];B[mq];W[pp];B[oo];W[qq];B[po];W[pq];B[ro];W[rp];B[qo];W[qi]
LB[qi:A][hq:B][ip:C][mo:D]
C[When Black covers from outside, White can live with sente and take the large point at A. Black's wall is not perfect as White can hope to later invade at B or C, and eventually cut at D. I like this for White. ]
))
(;B[oq];W[qo];B[po];W[qn];B[rp];W[pj]LB[np:A][oq:B]
C[This diagram shows how the opening proceeded in game 7. The exchange of White A for Black B can be seen as a slight gain for White. In game 7, White outspeeded Black in the opening and built a large area on the left side, and had what I thought to be a distinct advantage. That game ended in a half point win for White. ]
))

