(;GM[1]FF[4]SZ[19]AP[SmartGo:3.1.2]
GN[2017.11.03_AlphaGo_selfplay_14]
PW[AlphaGo]
PB[AlphaGo]
EV[AlphaGo selfplay]RO[14]
KM[7.5]
RE[W+R]
RU[Chinese]MU[1]
C[AlphaGo vs AlphaGo Game 14: A double kakaris and a new joseki
Commentary by Michael Redmond 9P
Editing/transcription by Chris Garlock and Myron Souris

In this game we're going to see a double kakari against a star point, a first for this series of games. In the Master vs. human series back in January, Master would play away when the opponent played a kakari against a star point, sometimes. Now we'll get to see how Master plays this with White, and it has a special move. Its a new joseki that actually make s some sense, so it's going to be interesting. ]
;B[qd];W[dp];B[pq];W[dd];B[nc];W[po];B[fc]
C[AlphaGo played this opening in 3 games of the self-played series.  Black's kakari here can be a ladder breaking move for a joseki variation in the lower right corner.]
(;W[qq];B[cf];W[df];B[dg];W[ef];B[cd];W[cc];B[ce];W[dc]
C[This could be called a favorite joseki for AlphaGo.  The Master version played this joseki with White in 2 games of the 60 game Master series, while this version played it with White in the team Go match in Wuzhen, and in 6 games of the self-played series.]
(;B[hc]LB[ic:A][de:B]
C[In the 55 self-played games, the upper left corner joseki (up to White's last most) was played 6 times and the 1-space extension here was played 4 times.  This was a new move unique to AlphaGo.  Compared to the wider extension at A, Black's move puts more pressure on White's group and keeps the option of pushing through at B.]
(;W[id]
C[In the 3 games in which White did not already have a stone on the upper side, AlphaGo played this shoulder hit every time.]
;B[hd]
(;W[ie];B[gf];W[gg]
(;B[eg]
C[A vulgar move.];W[ff];B[hf];W[fg];B[ci];W[jg];B[hg];W[fd]
C[White connects the corner group and threatens to cut Black.]
(;B[ed]LB[de:A]
C[A tesuji.  If White answers at A, Black will be connected on the right and can play away.]
(;W[di];B[dj];W[cg];B[ei];W[bg]LB[de:A]
C[With the sequence from the marked move, White is making the connection at A forcing.]
TR[di];B[bc];W[bb];B[ad];W[gd]LB[di:A]
C[White was setting up this move with the sequence from A.]
(;B[he];W[gc]LB[di:A]
C[In the sequence starting with A, White has taken profit on the upper side in return for losing some points on the left.  Black's profit on the left is big, and I would say this trade favors Black.]
;B[hi]LB[kd:A]
C[I would have played at A instead.];W[md];B[nd];W[me];B[mc];W[kd];B[ql]
;W[pr];B[qr]
C[Black's cross-cut is a very unusual move that works only when the ladder favors Black.]
(;W[pp];B[oq];W[or];B[nq];W[rr];B[ng]
C[Black attacks White on the upper side, while expanding the right side.]
;W[pk];B[on]
C[Making use of the cut at A, Black's move makes a loose connection.]LB[qp:A]
(;W[ph];B[kh]
C[Black is enclosing White from the center, and will force White to live on the upper side.]
;W[ne];B[pg];W[qg];B[pf];W[oh];B[nf];W[oe];B[qf];W[lc];B[pc];W[kg];B[lh]
;W[qk]
C[With this move, White's group on the right is settled.  Black has some potential to attack on the upper side, but Black is not strong enough on the outside to make it work at this time.]
(;B[fq];W[cn]
C[At this time, both sides have less than 30 points in territory.  White has some potential to expand the right side, while Black has a lot of stones in the center.  It is not clear to me who has an advantage at this time.]
;B[cq]
C[Black is trying to use its relatively strong position in the center to attack White in the lower left.]
;W[dq];B[dr];W[ck]LB[bi:A]
C[White threatens to connect at A.];B[bj];W[er];B[cr];W[fr];B[bo];W[gq]
C[White makes good shape on the lower side.  White's plan is to give Black some profit on the left, and take the initiative in the lower right quarter of the board.]
;B[co];W[do];B[dn];W[en];B[dm];W[em];B[el];W[dl];B[cm];W[bm];B[bn];W[fi]
C[With this attachment, White is starting to cut off Black's group on the middle upper side, and is also looking at some aji on the left.]
(;B[fl]
C[Black avoids the danger on the left.]
(;W[fj]
C[White puts Black into danger on the left again.]
(;B[dh]TR[fi:fj]
C[Black protects by capuring, and now has close to 40 points on the left, and a lead in territory.  With the 2 marked stones White is setting up an attack against Black's group on the middle upper side.]
;W[jh];B[ji];W[ii];B[ij];W[ih];B[hh]
(;W[jj]
C[Cutting on this side is correct.];B[hk];W[ki]LB[gl:A]
C[White captures a stone in the center.  White's group on the upper side was not completely settled, so part of the added value is that it is a strong group now.

Potentially, White can use this strong position in the center to help expand the right side.  Also, White has a potential cut at A to attack Black in the center.]
;B[ab];W[hb];B[lp]LB[iq:A][pn:B]
C[The right and lower sides are the remaining important areas.  Black's move here is well positioned to effect both sides, and makes miai of A and B.]
(;W[mo]
C[White enlarges the right side.]
(;B[lo];W[mn];B[iq]LB[lp:A]
C[The combination of A and Black's move here gave a good position on the lower side.]
;W[np]LB[oo:A]
C[White removes the threat of Black's move at A.  White's right side has expanded up to the sixth line with this move.]
;B[mp];W[op];B[ln];W[mm]
(;B[fp]
C[After this overplay, the game becomes difficult for Black.];W[hq];B[ip]
;W[gn]LB[gl:A][fp:B]
C[After White's jump here, it is already difficult for Black to kill White in the local position.  And White also has the option to cut at A that will make trouble for Black in the center.  Black's B is in danger of becoming mochikomi.]
;B[fm];W[fn];B[ho];W[ik];B[hj];W[hn]
C[White's push here threatens to attack Black in the center.]
(;B[il]LB[gl:A]
C[Black adds a stone to the center group.  I get the impression that AlphaGo is trying to maintain the illusion that Black is attacking White, because this hane does not really prevent White's cutting move at A.  Black is in more danger than White here.]
;W[io]
(;B[hr]LB[gr:A]
C[Black's hane was a bad exchange when White answered at A.];W[gr];B[hp]
;W[gp];B[ir];W[jm]LB[ep:A][gl:B][mq:C]
C[White can make a seki by playing at A instead, but can be more active with this game move.  White has potential to cut at B to attack in the center, or cut at C to attack Black on the side.]
;B[kl];W[gl];B[gk];W[fk];B[gm];W[hm]
(;B[ek];W[im]LB[ep:A][jo:B]
C[After this move, White is alive with a move at A or B.];B[nr];W[jo];B[lk]
;W[lr];B[kr];W[kq];B[kp];W[jr];B[lq];W[ks];B[jp]TR[kq][jr][lr][ks]
C[After Black connects here, White's marked stones are not completely dead yet.]
(;W[km]
C[White's push here offers to allow Black to connect in the center, after which White can win by finishing the right side territory.]
(;B[ns]
C[Black's descent captures 4 stones on the lower side, making some territory.]
;W[hl];B[jk];W[mk]
C[White's contact play is asking for Black to connect in the center, so White can finish the right side territory.]
(;B[mj];W[li];B[ml]LB[lm:A]
C[Black's move here is dangerous, but the safe move at A would not be good enough, so I can agree with this choice.]
;W[lm];B[ok];W[pl];B[mi];W[jl]LB[lj:A]
C[This is already a ko, as White can follow up with a move at A.];B[ol]TR[hg:hh]
C[If one ignores the fact that Black's marked group is in danger of being cut of by the ko, Black is gaining by reducing White's right side territory.  So White must gain something in the ko fight to secure a win.]
;W[pm];B[ic];W[mh];B[nh];W[lg];B[oj];W[qh];B[cb];W[fb]
C[Black has a total of almost 80 points of territory, While White has about 60.  White must gain at least 10 points with the ko.]
(;B[om]LB[pn:A]
C[Black's connection here is a big move that makes some ko threats for Black at A.]
;W[ik];B[pn];W[qn];B[il];W[ch]
C[White's move here threatens to capture Black on the left side.]
(;B[bi];W[ik];B[qm];W[rn];B[il];W[pd];B[qc];W[ik];B[db];W[ec];B[il];W[lj]
;B[nk];W[ik];B[qp];W[qs];B[il];W[oc];B[ob];W[ik];B[rq];W[qr]LB[kk:A]
C[White was at a point where White could have finished the ko with A instead, and won by a larger margin.]
;B[il];W[mb]LB[kk:A][nb:B]
C[Because White has another ko at A, this is not a direct ko yet, and it is logical that White is not playing the bigger ko threats.  I get the feeling that White is not seriously trying to win the ko in any case, and has probably calculated that a cut at B will be good enough to win.]
;B[kk]
C[Finally, Black makes it a direct ko.];W[ik];B[kj];W[ji];B[il];W[cl];B[cn]
;W[ik];B[rk];W[qj];B[il];W[cp];B[bp];W[ik];B[rp];W[qo];B[il];W[ej];B[dk]
;W[ik];B[qi];W[pi];B[il];W[nb]
(;B[sr]
C[Black's hane seems unreasonable, as this corner is not nearly as big as the ko in the center.  AlphaGo seems to realize that White is going to win anyway, so Black's move can be seen as an attempt to muddy the waters.  Black was forced to play some point-losing ko threats after this, so strictly speaking, this move was a mistake that cost Black a couple of points.]
;W[ik];B[pj];W[ri];B[il];W[rf];B[re];W[ik];B[rj];W[qi];B[il];W[bd];B[be]
;W[ik];B[rm];W[sm];B[il];W[mr];B[mq];W[ik];B[eo];W[fo];B[il];W[ni];B[oi]
;W[ik];B[ep];W[eq];B[il];W[bq];B[br];W[ik];B[sl];W[rl];B[il];W[of];B[og]
;W[ik];B[fh];W[gh];B[gi]
C[Black's last couple of moves create yet another ko attached to Black's group on the upper side, but practically this is just a ko threat.  Black stands to lose too much on the left side for this ko to be playable.]
;W[eh];B[di];W[fh];B[il];W[os]LB[rs:A][ik:B]
C[White finally uses the endgame move here in the lower right corner as a ko threat.  If Black starts a ko with A, it will be a double ko with the ko at B.]
;B[ik];W[rs];B[ss];W[sq];B[oa];W[hs];B[is];W[sg];B[ib];W[eb];B[ba];W[na]
;B[pb];W[jc];B[ha];W[jb];B[ja];W[ka];B[if];W[jf];B[ia];W[od];B[gb];W[se]
;B[sd];W[sf]
C[White is winning by 1.25 stones (3.5 points)])
(;B[ik]
C[If Black connects the ko, ...];W[rf];B[re];W[sf];B[sr];W[ro];B[os];W[sp]
;B[pe];W[od];B[oa];W[jc];B[ib];W[ha];B[jb];W[kb]
C[... there are only a few large endgame moves left.  White wins by 0.25 stones (1.5 pts )]
))
(;B[ik]VW[aa:ks];W[cl];B[cn];W[ej];B[dk];W[cj];B[di];W[bi]
C[White captures Black.]))
(;B[ik]
C[Even if Black connects the ko, ...]VW[aa:ss];W[lj]
C[... White can force here to make a ko.];B[nk];W[kk]))
(;B[lm]VW[ha:ss];W[ml];B[ll];W[rg]
C[White wins.]))
(;B[lm]VW[aa:ss];W[ml];B[ll];W[rg];B[mk];W[nk];B[nj];W[ok]
C[If Black connects in the center, surrounding the right side is good enough for White to win.]
))
(;W[mr]VW[al:ss];B[os];W[qs];B[mq];W[ms]LB[ns:A][jq:B]
C[White can connect at A or live with B.]))
(;B[hl]VW[ag:ms];W[ek];B[gl];W[im];B[dk];W[cl];B[cn];W[jo]
C[White lives, while pressuring Black on the lower side.  White will win easily.]
))
(;B[hp]VW[ai:ls];W[gp];B[ir]LB[hr:A][gr:B][go:C]
C[The A-B exchange that Black played in the game was bad.  In this sequence without that bad exchange, Black can push through at C next.]
))
(;B[gp]
C[If Black pushes from the inside, ...]VW[aa:ss];W[hp];B[go];W[io];B[in]
;W[jo];B[jn];W[gl];B[gm];W[hm];B[gk];W[fk]TR[el:fl][fm]
C[... White squeezes the marked stones to cut Black off in the center.]
(;B[ek];W[hl]
C[If Black pushes through (marked), White can capture Black in the center here.]
TR[ek];B[il];W[im];B[jk];W[jm];B[kn];W[kk])
(;B[hl];W[ek]
C[Black can save the group in the center by capturing (marked) and allowing White to squeeze here.]
TR[hl];B[gl];W[im];B[jm];W[il];B[dk];W[cl];B[cn]LB[hl:A];W[ir];B[jp];W[jr]
;B[lr];W[eq]
C[White scoops out the lower side (marked), and finally connects to the center.  Black has accomplished nothing with the attack against White in the lower left, and will now have to make eyes for Black's group on the side.  White wins.]
TR[jr])))
(;B[gn]VW[aa:ss];W[hq];B[ir];W[fo];B[nr]
C[I suggest that Black has a small lead with this sequence.  Black has a total of more than 70 points, and the outcome will depend on how much White can make on the right.]
))
(;B[oo]VW[aa:ss];W[pn];B[pm];W[om]LB[gl:A]
C[When Black tries to reduce the right side, White will fight strongly here.  One must remember that there is a potential cut at A, so it will be dangerous for Black to have weak groups on the right and lower sides.]
))
(;W[jq]
C[If White extends on the lower side, ...]VW[gh:ss];B[qp];W[rq];B[pn];W[qo]
;B[qn];W[ro];B[mn]
C[... Black will reduce the right side by forcing with this sequence and then connecting here.  Black has a lead in territory.]
))
(;W[hj]VW[aa:ss];B[fh];W[gh];B[gj];W[hk];B[gi];W[gk];B[fk]
C[When White cuts directly (marked), Black can play this sequence to set up a squeeze.]
TR[hj];W[eh];B[ej];W[fh];B[de];W[fe];B[ec];W[hb];B[gm];W[ik];B[iq]
C[In this trade, White has captured Black on the upper side, while Black gets the upper left corner, and White's gain in territory is small.  Black has the initiative on the lower side and will win this game.]
))
(;B[ih]VW[aa:js];W[dh];B[eh];W[ch];B[ej];W[cj];B[cl];W[bl];B[dk];W[bk]
C[If Black plays away (marked), White can capture the left side with this sequence.]
TR[ih]))
(;W[dh]VW[aa:js];B[eh];W[ch];B[ej];W[cj];B[bi]
C[White loses the semeai on the side.]))
(;B[fj]VW[aa:ms];W[ek];B[fl];W[cl];B[cn];W[fk]
C[If Black covers (marked), White will force this sequence, and White is looking to exploit Black's shortage of liberties on the left.]
TR[fj]
(;B[gk];W[gl];B[fm];W[gj];B[hk];W[fn];B[gm];W[gn];B[hm];W[dh]
C[When Black covers (marked), White will play this forcing sequence and finally atari here to capture Black on the left.]
TR[gk];B[eh];W[ch];B[ej];W[cj];B[dk];W[bi]
C[White wins.])
(;B[gl];W[gk];B[dk];W[dh];B[eh];W[ch];B[ej];W[cj]LB[gj:A][bi:B]
C[When Black tries to capture White, White can cut to make miai of A and B.]
;B[bl];W[bi];B[bk];W[ci];B[gj];W[bf];B[be];W[af]
C[Even if Black squeezes (marked) to take away White's eye space, White can win the semeai on the left.  This is good for White.]
TR[bl])))
(;B[lf]VW[aa:sm];W[lg];B[mf];W[jh];B[ji];W[mh];B[nh];W[ii]
C[If Black had a stronger outside shape, this attack could be troublesome for White.  As it is, Black falls apart on the outside.]
))
(;W[pn]VW[ia:ss];B[om];W[pm];B[pl];W[ol];B[ok];W[nl];B[nk];W[ml];B[pj]
C[If White pushes through (marked), Black can take profit on the right with this sequence.]
TR[pn]))
(;W[oq]VW[gh:ss];B[pp];W[qp];B[op]
C[White cannot capture with the ladder.]))
(;B[de]
C[Because of damezumari on the left, Black cannot cut here.]VW[aa:lk];W[ee]
;B[ec];W[be];B[bf];W[af];B[bd];W[ab]
C[White can win the semeai on the side.]))
(;W[ec]VW[aa:sl];B[gd];W[md];B[nd];W[me];B[mc];W[kd];B[hi]LB[fe:A]
C[Black plays the triangled exchange before protecting (square), and this gives Black some extra profit.  Black can force with A at any time to make a living shape on the side.]
TR[ec:ed]SQ[gd]))
(;B[gd]VW[aa:sm];W[md];B[nd];W[me];B[mc];W[kd]
C[If Black simply answers White for the marked exchange, White is connected and can switch to the right with this sequence.]
TR[fd:gd]))
(;B[hf]VW[aa:lk];W[fg];B[ci]LB[eg:A][ff:B]
C[In the game, Black played the A-B exchange, but it is better for Black not to.]
))
(;W[fd]VW[aa:mj];B[gd]LB[id:A][hd:B]
C[This diagram is offered as my explanation of why AlphaGo plays the shoulder hit at A.

At some point, White will want to attach to connect White's corner group, after which I said previously that Black's move here would give good shape.  The A-B exchange completely changes that, and Black's move becomes an empty triangle, which is bad shape.

White is not ready to attach yet, and I expect Black will try to find a better move than Black's move here.  But the fact remains that White A was a part of the preparations to make White's attachment good shape for later in the game.]
))
(;W[fd]VW[aa:kj];B[gd]LB[hc:A]
C[When White attaches to connect, Black makes good shape with the stone at A, and this is bad for White.  This shows how the Black A is an effective attack against White's group.]
))
(;B[gd]
C[The most popular 'human' move would be this kosumi, with which Black threatens the cut at A and hopes to strengthen Black's groups on both sides, while putting pressure on White's group in the corner.]
LB[de:A]VW[aa:kk]))
(;W[cf];B[qm];W[qq];B[qp];W[pp];B[qo];W[qn];B[rq]
C[Black's hane is a variation of the joseki that involves a ladder that the marked stone breaks.]
TR[fc]
(;W[qr];B[rn];W[pn];B[oq];W[rm];B[ro];W[rl];B[rr];W[pl];B[id]TR[qm]
C[When White cannot capture the marked stone in a ladder, the net leaves forcing moves for Black and is inefficient.  This is good for Black.]
)
(;W[pn];B[qr];W[rm]
C[White can avoid the ladder with this variation, which is considered to be even.]
)))

