(;GM[1]FF[4]SZ[19]AP[SmartGo:3.1.3]CA[shift_jis]
GN[17_AGKJ_annotated]
PW[AlphaGo]
PB[AlphaGo]
EV[AlphaGo selfplay]RO[17]
KM[7.5]
RE[W+R]
RU[Chinese]MU[0];B[qd];W[dc];B[dq];W[pp];B[cn]LB[ce:A][de:B]
C[As I mentioned in game 13 with the same position, Black 5 is unusual in that Black is playing tightly. Human pros believe that Black should play actively in the opening to take advantage of the first move initiative, and to make up for the komi that Black must pay. Common moves for Black would be A or B.  ]
;W[cf];B[nc]
(;W[nq]
C[In this game White 8 is played towards the lower side, while in game 13 White played towards the right. Both sides are identical in their relation to the adjacent corners, and are an equal value.]
;B[qn];W[qo];B[pn];W[pj];B[mn];W[mp];B[qh]LB[qo:A][mn:B]
C[In this first fight, Alphago is playing shapes that are common in human games, with White kicking at A before the pincer, and Black combining the jump at B with a pincer at 15. ]
;W[oe]TR[pj]
C[White 16 forces Black to add a stone to the corner. By inducing Black to reinforce the corner White takes a local loss, as the corner was not completely territory yet. White will use this with the marked stone to make good shape in this area of Black's strength, and this will be a good example of how AlphaGo makes sabaki. ]
;B[pd];W[ph]
C[White's plan is to force from above, giving Black some territory on the side, while creating a strong White group in the center (see var). ]
(;B[pi];W[oi];B[qi];W[oj];B[qj];W[pg];B[nh];W[oh];B[ql];W[le]
C[White plays yet one more move in the center with W28. There are large opening points on the sides, but strengthening the White group and controlling the center are more important for White. ]
;B[jq];W[pl]LB[qq:A][ro:B]
C[I do not understand White 30. There is some aji with a Black invasion at A, so I might have played at B to complete the corner territory with this move. ]
(;B[df]
C[Black's attachment at 31 against White's ogeima shimari was played only twice in the 50 AlphaGo self-play series, but even so it has attracted attention. Many human pros are experimenting with this move now, while it was rare before AG (3 vars added). ]
(;W[de];B[cg];W[dg];B[ef];W[ch]
(;B[bg]
C[With B37, Black's plan is to take a position on the left side and give White the center. This is not usually good for Black, and the normal move is to cut on the 3rd line (see var). ]
;W[ce];B[ci];W[eg];B[dh];W[eh];B[di]
(;W[ff];B[ei];W[lc]
(;B[jo];W[in];B[jn];W[il];B[hi];W[jm];B[hm];W[im];B[go];W[gn];B[qq];W[ro]
;B[pq]
(;W[op]
C[This brings me back to my comment on move 30 (marked), where I think White should have added a move to the lower right corner. As the variation shows, it is not easy for White to kill Black's invasion. ]
TR[pl];B[or];W[nr];B[rr]
C[Black is alive in the corner. ];W[on]
C[White connects to the center. ]
(;B[qg];W[io];B[ip];W[kn]LB[hp:A]
C[White connects the marked groups, starting to make some territory in the center and filling a liberty to make White A effective next. ]
TR[oj][im:jm][on][mp][op];B[ko];W[lo];B[hp];W[qf];B[rf];W[co]
(;B[om];W[ln];B[dn];W[cq];B[dr]
(;W[pf]LB[qe:A][re:B]
C[White's connection here actually has a relation to a potential ko in the lower left corner, shown in the variation. If Black answers at A, White will have some ko threats starting with the cut at B. ]
;B[fn]LB[fn:A]
C[Black A was a big move for territory, and now Black should be able to kill White in the LL corner. ]
;W[re];B[rg];W[rd]
(;B[qb]
C[Black should have covered on the second line.];W[qe];B[rc];W[fm]TR[cn:dn][fn]
C[White's hane here starts a sequence of moves, whith which White might seem to be trying to live inside, but actually White is just cutting the marked Black stones away from Black's lower side group, thus creating some forcing moves to strengthen White in the center. ]
;B[em];W[dp];B[cr];W[fp];B[fr];W[bn];B[bm];W[fo];B[en];W[gr];B[hr]LB[bp:A][br:B][hn:C][fl:D]
C[White A will be answered by Black B, so White can't live in the corner. By cutting Black at the marked points, White has created forcing moves at C and D, which will be explained as the occur in the game. ]
TR[gn][fo];W[hg]
C[White surrounds the upper side, and this game seems to be entering the final stage. White's upper side is comparable in size to Black's lower left area, and then Black has three small territories on the right, while White still has some potential in the center. The game is going to be close. ]
;B[pm];W[hn]
C[White's connection threatens Black on the lower side. ]
(;B[gq]
C[Black cannot play away with this move. ];W[fl]LB[fl:A]
C[White's extension at A is threatening Black on the left side. ];B[db]LB[db:A]
C[Black A is a ko threat-like move that might look strange, but will actually have some meaning later in the game. For now, the upper left corner is bigger than the lower left. ]
;W[bp]
C[The upper side and the lower left are close in size, but actually I think the upper side is bigger. Therefore, I cannot explain why White played here in the LL corner. ]
(;B[br]
C[Black simply answers in the corner. ];W[ec]
(;B[ek]
C[AG scared me a bit there with an exchange of ko threat-like moves, but both sides have finally protected, and we are back in the endgame. ]
;W[mb]
C[While White a is not sente, it is a huge endhame move, and it would have been sente for Black. ]
LB[mb:A];B[md];W[ld];B[ki];W[do];B[bq];W[ob];B[nb];W[na];B[pb];W[jg];B[ih]
;W[ig]
(;B[bb]
C[In short, Black is trying to gain a point, or actually what is technically called a fraction of a point, with this move. I will attempt to explain, starting with what might be called the normal endgame play for Black. ]
(;W[bc]
C[White refuses to give in the fraction of a point with this move. ];B[bd]
(;W[cd]
C[Again, White plays the strongest move, refusing to give up a fraction of a point. ]
;B[ac];W[cc];B[bf];W[oc];B[od];W[be];B[ae]
C[If Black can win this ko, Black's profit in this corner will be big. However, it turns out that White's choice to play this ko was correct, and Black will not have enough valid ko threats. The question remains, was it necessary for Black to start this complicated exchange with Black A? The game was extremely close in any case. ]
LB[bb:A];W[ad];B[ml]
C[Black A is a ko threat that threatens to cut at B. ]LB[ml:A][km:B];W[lk]
;B[bd];W[pc];B[qc];W[oa];B[pa];W[ma];B[ra];W[ad];B[mk];W[ne];B[bd];W[el]
;B[dl];W[ad];B[lj];W[nm]LB[km:A][nm:B][ij:C]TR[el:fl][il:im][fm][jm]
C[While Black is threatening to cut at A, White is defending indirectly with B. If Black cuts now, White's marked group can make a living shape if White plays at C, so White B works to reinforce the White group in the LR corner while putting some pressure on Black in the center. ]
;B[bd];W[dk];B[cl];W[ad]
(;B[nl];W[lm]
C[Black's attempted ko threats in the center have met with strong resistance by White, and White has created a weakness in Black's connection. ]
;B[mm]
C[Black adds a move to protect the center, giving up the ko on the left. ]
;W[af]LB[bh:A]
C[White wins the ko. Even if we assume that Black will return to protect at A, this ko fight in the UL corner has cost Black two points when compared to the normal endgame sequence. ]
;B[nd];W[mi];B[bh];W[gj]LB[ej:A][hj:B]
C[Locally, this move makes miai of A and B. ];B[hk]
C[Black jumps in to reduce White's territory here, and is also attempting to attack the marked White group. ]
TR[im:jm][kn][lo][mp][op];W[kp];B[jp];W[kq]
C[This is a big move that makes some eyespace on the lower side. ];B[gk]
;W[fk];B[gm]LB[ej:A]TR[gj][fk:fm][el]
C[With this cut, Black will chase White's marked group and get a forcing move at A, which increases Black's territory on the left. ]
;W[hj];B[ik];W[ij];B[jk];W[fi];B[ej];W[fj];B[ll];W[sq];B[sr];W[kh];B[ni]
LB[ni:A]
C[Black A was a clever move that set up an endgame sequence in the center. ]
;W[jr];B[ir]
(;W[ji]
C[It is correct for White to make territory on the left, instead of trying to capture the two marked Black stones. ]
TR[nh:ni];B[kr];W[pr]
C[Black cuts to start a forcing endgame sequence that threatens White's eyespace for the marked group. ]
TR[mp];B[qr];W[oq];B[os];W[lr];B[kl];W[km];B[js];W[ls];B[li];W[lh];B[mh]
;W[nj];B[mj];W[mf]TR[kf:kg][lf]LB[mf:A][ng:B]
C[White A is the correct move here, making territory on the marked points and setting up White's next local move at B. ]
;B[rm];W[ho];B[gp];W[ns];B[ps];W[ng];B[oo];W[no];B[po];W[qp];B[mo];W[rq]
;B[pk];W[mg];B[mi];W[jj];B[ag]
(;W[sn]
C[White could have simply connected to win by the smallest margin. As the variation shows, White must win the final ko, and has an advantage of just one ko threat. ]
(;B[ae]LB[ae:A][bd:B][sn:C]
C[When Black takes at A, the size of this ko is getting big, and it becomes more difficult to judge the trades that might happen with White's ko threats. If White is forced to connect at B, this will entail a two point loss for White in trade for only one point gained with White C, and White will lose by the smallest margin.]
;W[sm]
C[If Black takes at A, White can use B as a ko threat, and White will have enough ko threats and a lead in territory. ]
LB[bd:A][rk:B];B[sl];W[af];B[rn];W[so];B[ae];W[rk];B[rl]
(;W[ok]TR[bl]
C[White did not need to play this move now, which again makes me think that the marked ko threat was not a part of White's calculations. ]
;B[ol];W[af];B[fh];W[fg];B[ae];W[qk]LB[pl:A][rj:B][qs:C][ck:D][bl:E][mc:F][lp:G][rp:H]
C[If Black answers this ko threat at A, White will win the ko on the left, and the game. White has ko threats at B, C, and D (still assuming that AG doesn't play the better ko threat at E), Black also has only three ko threats at F, G, and H, and White wins by one threat. ]
;B[bd];W[rj]LB[ad:A][ri:B][cb:C][eb:D]
C[If Black now connects at A, White will capture the right side with B, and assuming Black C and White D, White has gained a few points in this trade and will win the game. ]
;B[ri];W[pl];B[mc];W[lb];B[pk]LB[ad:A][af:B]
C[At this point, White has more than one way to win. White could switch back to the ko at A, and if Black connects on the right, White will be able to win the ko at B, and the game. ]
;W[bk]
C[White A is not the optimal ko threat, and White would have had two ko threats here if it had played at B. ]
LB[bk:A][bl:B];B[ck];W[pl];B[eb];W[pk]
C[White finishes the ko on the right, gaining about 35 points. If Black now connects at A, White will simply cover at B, allowing Black to connect the ko on the left, and White wins easily. ]
LB[cb:A][fb:B];B[gb];W[cb];B[ca];W[fc];B[fb];W[hb]
C[White has enough territory to win even if Black connects the ko. ]
(;B[gc];W[ad]
C[W+1.25 (3.5)])
(;B[ad];W[gc];B[ga]LB[ad:A][ga:B]
C[While connecting at A and then making an eye with Black B might be called the correct endgame sequence, it will not be good enough for Black to win. White's profit on the right side was too big. ]
;W[ha];B[sk];W[sj];B[sd];W[se];B[sc];W[ks];B[jr];W[np];B[nn];W[kj];B[kk]
;W[lp]
C[White wins by 1.25 stones (2.5 points).])
(;B[nn]LB[nn:A][np:B]
C[This variation will show what would have happened if Black had not resigned. The exchange of Black A for White B has no special meaning, but is added to separate this from the game variation. ]
;W[np]
C[The exchange has no meaning. I have added it to separate this sequence from the main variation, and the following moves will show how the game would have continued if Black had not resigned.]
;B[gc];W[ad]LB[nn:A][np:B]
C[For all practical purposes, the exchange of A for B can be ignored, and this is the same as the position in which Black resigned. In this dexcisive ko on the left, both sides have a number of local ko threats. ]
;B[hc];W[ib];B[bd];W[da];B[ea];W[ad];B[jb]
C[Black A loses a few points, but is the only way for Black to create enough ko threats to win the ko. ]
LB[jb:A];W[ic];B[bd];W[ba];B[aa];W[ad];B[id];W[jc];B[bd];W[qs]LB[lp:A][sc:B]
C[Black has a fairly large ko threat at A, but White also has a valid ko threat at B. Black must finish the ko now. ]
;B[ad];W[pr];B[fd];W[ed];B[fe];W[ee];B[he];W[ge];B[gd];W[gf];B[ga]LB[ga:A]
TR[ba][da][fa][ab][af]
C[Black A is a big move that makes all the marked points Black territory. ]
;W[jd];B[je];W[ke];B[ha];W[ia];B[sk];W[sj];B[sd];W[se];B[sc];W[jf];B[ie]
;W[ks];B[jr]
C[White wins by 1.25 stones (3.5 points).]))
(;W[af];B[ok]LB[af:A][ok:B][bl:C]
C[If White had simply taken at A, then White would still have a ko threat at B to use next, making the ko relatively easy for White to win. So, what if Black plays at B? In this case, White can finish the ko on the left and the outcome will depend on the final ko again, and with two ko threats at C, White will win. ]
;W[ae];B[mc];W[lb];B[ks];W[sc];B[sb];W[sf];B[sg];W[se]TR[bl]
C[White can win the final ko with 2 ko threats at the marked point, and wins by 0.25 stones.]
))
(;B[sm]LB[sm:A]
C[If Black covers at A, then White has a relatively easy win, as White will now win the final ko with an extra ko to spare. ]
;W[ok];B[ol];W[ae];B[rn];W[so];B[mc];W[lb];B[ks]LB[ks:A][sn:B][is:C]
C[When Black ends up playing the final point at A, instead of gaining a point by playing at B, this gives White an extra ko threat at C that will make winning the final ko easy for White. ]
;W[sc];B[sb];W[sf];B[sg];W[se];B[nn];W[np];B[sd];W[kj];B[kk];W[sc];B[pe]
;W[me];B[sd];W[gl];B[hl];W[sc];B[lp];W[lq];B[sd];W[qk];B[rk];W[sc];B[jl]
;W[lp];B[sd];W[qs];B[rs];W[sc];B[rp];W[sp];B[sd];W[is];B[hs];W[sc];B[fh]
;W[fg];B[sd];W[ck]LB[ck:A][bl:B]
C[White can use this easy ko threat at A, instead of the relatively complicated ko threat at B. Black is already out of ko threats. ]
;B[bk];W[sc];B[nk];W[sd]
C[White wins by 0.25 stones, or half a point. ]))
(;W[ok];B[ol];W[ae];B[mc];W[lb];B[sn];W[so];B[rn];W[sc];B[sb];W[sf];B[sg]
;W[ks];B[jr]
C[After White connects at A, the rest of the moves are fairly easy to understand. The final ko will be in the upper right. ]
LB[ae:A];W[se];B[nn];W[np];B[sd]LB[nn:A][np:B]
C[Black exchanges A for B before taking the ko. Otherwise, White could have used B as a ko threat. ]
;W[kj];B[kk];W[sc];B[pe];W[me];B[sd];W[bl]LB[bl:A]
C[This ko threat at A did not show up in the game variation, and I believe it might have been missing in AlphaGo's calculation. With this move, White has two ko threats on the left side. ]
(;B[bk];W[sc];B[fh];W[fg];B[sd];W[am];B[al];W[sc];B[lp];W[lq];B[sd];W[gl]
;B[hl];W[sc];B[jl];W[lp];B[sd];W[qk];B[rk];W[sc];B[rp];W[sp];B[sd];W[qs]
;B[rs];W[sc];B[nk];W[sd]
C[Black runs out of ko threats, and the game ends with White filling the ko. White wins by 0.25 stones with Chinese rules, or half a point in the Japanese counting system. ]
)
(;B[sc];W[am]
(;B[cm]
C[If Black connects here, White will not get eyes, but this will become a dangerous ko that puts the whole Black group on the left in danger. White has two ko threats on the right, and Black has no valid ko threats for this ko. ]
;W[ck];B[bk];W[ak];B[al];W[qk]LB[qk:A][pl:B][qs:C][rk:D][sc:E]
C[White A threatens a ko at B, and White can use ko threats at C and D to make it work. All White needs is to gain a point back after losing the ko at E, so this ko threat is more than big enough. ]
;B[rk];W[bl];B[bj];W[eo];B[al];W[qs];B[rs];W[bl];B[fg];W[dm];B[fh];W[fe]
C[This is a big win for White. ])
(;B[ck]LB[ck:A][fg:B][lp:C]
C[When Black pushes through at A, this will become a ko for White to live on the side. Black has one local ko threat, but the threats at B or C are just not big enough. White has two ko threats on the right and can win this ko. ]
;W[cm];B[bk]LB[bk:A]
C[Covering at A is a must. Allowing White to crawl here would just make things worse for Black. ]
;W[ao];B[dm];W[bm];B[cp];W[qk];B[rk];W[cq];B[aq];W[ap];B[cp];W[qs];B[rs]
;W[cq];B[lp];W[cp];B[lq];W[mq];B[ak];W[gl];B[hl];W[eq];B[er]
C[A was Black's biggest ko threat, but it wasn't enough. White will win by 2.25 stones, or 4.5 points in the Japanese system. ]
LB[lp:A]))))
(;W[nj];B[lh];W[mh];B[kl];W[km];B[ii]LB[nj:A][lh:B][ii:C][fh:D]
C[If White plays at A, Black will hane at B once, and then pull out the stones on the left with C. Next, Black threatens to cut at D. ]
;W[gh];B[kg];W[jh];B[li];W[kf]LB[gh:A][kg:B]
C[After White protects at A, Black will switch back to the right with B, breaking into White's center territory. ]
;B[kr];W[lr];B[js];W[pr];B[os];W[oq];B[qr];W[ns];B[ps];W[ls]LB[kr:A]TR[lo]
C[The endgame sequence starting with Black A is sente as it threatens the marked White group. ]
;B[ji];W[lg];B[oo];W[no];B[po];W[qp];B[mo]LB[ji:A][lg:B][oo:C]
C[Finally Black will connect at A, allowing White B, and Black plays the final big point at C. Black will win by 0.75 stones, or 1.5 points in the Japanese counting system. ]
))
(;B[nn];W[qk];B[rk];W[pk];B[rm];W[mm];B[nl];W[lm]LB[nn:A][km:B][oo:C]
C[If Black covers at A, White can play this sequence to prevent the cut at B and prepare a big move at C. This is bad for Black. ]
))
(;W[cc];B[ae];W[af];B[bf];W[be];B[ag];W[ac]LB[cc:A][bh:B][ad:C][af:D]
C[If White simply connects at A, Black gains a fraction of a point compared to what I am calling the normal endgame sequence. Eventually Black B will be exchanged for White C, and if Black can win the final ko at D, Black will have gained a point. ]
))
(;W[cc];B[ae]
(;W[af];B[bf];W[be];B[ag];W[bd]LB[cc:A][af:B][bh:C][ad:D]
C[When White plays at A, White can still protect the corner territory by sacrificing a stone at B. Near to the end of the game an exchange of Black C for White D can be expected. If Black can win the final ko at B, Black will have gained a point when this is compared to what I called the normal endgame play. ]
)
(;W[ad];B[fh];W[fg];B[bd];W[af];B[be];W[bf];B[bc];W[cb];B[ba]LB[bb:A][cc:B][ad:C]
C[After the exchange of Black A for White B, White's attachment at C does not work this time. Black can live without a ko, and this is good for Black.]
)))
(;B[ae];W[ad]
(;B[af];W[bd];B[ml];W[lk]LB[ae:A][bf:B]TR[ch]
C[Sliding at A is what I would normally call the correct endgame play. With the marked White stone getting in the way, it is dangerous for Black to slide in further than this. Black A avoids the shortage of liberties and reduces White's territory more than curling at B would have. When I asses the game move, this diagram is the result that I will be comparing with. ]
)
(;B[bd];W[af];B[be];W[bf];B[bc];W[cb];B[bb];W[ba];B[cc];W[da];B[ca];W[cl]
LB[ad:A][bd:B][cl:C]
C[When White attaches at A, Black might try the hane at B to make this ko fight. However, White has a number of valid ko threats at C, and this ko will end as a failure for Black. ]
)))
(;B[ji];W[do];B[bq];W[cl];B[cm];W[fj];B[fi];W[ck]LB[cl:A]TR[cm][em][dn]
C[If Black plays away, White can peep at A and then cut off the marked Black group. This is bad for Black. ]
))
(;B[cc];W[ec];B[eb];W[fb];B[bd];W[cb];B[bb]LB[cb:A][gb:B]
C[Black can easily live in the corner. White's cut at A removes the danger of Black clamping at B. ]
;W[am];B[al];W[an];B[cl];W[br]
C[White lives with A. In this trade of the UL corner for the LL corner, White seems to have gained some points. ]
LB[br:A]))
(;B[fl];W[bp];B[br];W[do];B[bq];W[gp];B[ho];W[hq]LB[bp:A][hq:B]
C[If Black plays away, White can gain some liberties by forcing with A, and then cut Black off with B. ]
;B[iq];W[gq];B[gs];W[ir];B[hs];W[jr];B[kq];W[kr];B[lq];W[lr]
C[White wins the semeai.]))
(;B[rc];W[rb];B[qc];W[qe];B[md];W[ld];B[mb]LB[mb:A][sc:B][lb:C]
C[The virtue of this diagram for Black is that Black's move at A is a big endgame move, and it is good to play it now before White grabs this important point. Next, B and C are miai. ]
;W[sc];B[lb];W[kb];B[qb];W[ob]LB[sc:A][lb:B][jb:C]
C[If White plays at A, Black can crawl once at B, reducing White's side territory and creating some aji with a clamp at C. When White plays the vital point inside Black's territory, this might look scary, but actually Black can easily make a living shape. ]
;B[sb];W[sa];B[qa];W[sd];B[pb]
C[Black is alive. ]))
(;W[bn];B[bm];W[bp]LB[an:A][ao:B]
C[White can make trouble in the corner with this hanging connection. If Black now plays an atari at A, White will start a ko by playing at B. ]
;B[br];W[dp];B[fq];W[en]LB[br:A][en:B][cm:C]
C[If Black tries to capture White without a ko by playing at A, White B is the tesuji to escape. White is threatening a cut at C, and this is troublesome for Black. ]
))
(;B[ln];W[km];B[om];W[nm];B[nn];W[oo];B[nl];W[pm];B[ol];W[pk];B[qm];W[ml]
LB[ln:A]
C[Cutting at A does not work for Black. White will capture the Black stones in the center. ]
))
(;B[om];W[nn];B[nm];W[pm];B[qm];W[mm]LB[om:A][mm:B]
C[If Black tries to cut White off with A, White can capture the cutting stones with B. ]
))
(;W[oq];B[rp];W[pr];B[qr];W[or];B[sq]LB[oq:A][sq:B]
C[When White bumps against Black at A, Black does not have room to live in the corner. However, Black's move at B sets up a connection on the side. ]
;W[rr];B[rs];W[sr];B[so];W[rn];B[rm];W[sn];B[op];W[oo];B[po]TR[rn:ro][sn][qo]
LB[so:A]
C[Black's hane at A causes White to fall into damezumari. In this final shape, Black has captured the marked White stones. ]
))
(;B[jn]
C[I would have played this two space jump with Black. ]))
(;W[ei];B[ff];W[ej];B[dk];W[hh]LB[ei:A]
C[If White pushes at A, this becomes a fight in the center. White takes the initiative, while Black has a lead in territory if it can handle the marked weak group skillfully. This is an even fight. ]
TR[df:ff]))
(;B[ce];W[bg];B[bf];W[cg];B[dd]LB[ce:A]
C[Black can cut at A and try to take the corner. White now has a choice to run out with one stone, or to start a ko in the corner (2 vars for White's move). ]
(;W[ee];B[ed];W[fe];B[cd];W[fd];B[ec];W[fc];B[fb];W[gb];B[eb]LB[ee:A]
C[If White runs out at A, Black can takethe corner territory with this sequence. In this board position, this is good for Black. ]
)
(;W[cd];B[ee];W[be];B[qq]LB[bd:A][ec:B]
C[When White plays this way, Black can play at A for a huge ko in which White will ignore any ko threat to win the ko, or Black can just cover at B, but that will be a good result for White locally. Black will leave the upper left, and try to make a big ko threat in the LR corner. This is a volatile situation that will end in some kind of a trade. ]
)))
(;W[dg];B[ce];W[de];B[ef];W[cd];B[cg];W[be];B[bf];W[ce];B[dh]LB[dg:A][ce:B][dh:C]
C[If White plays a hane outside at A, this sequence will follow. The players need to be aware of the situation with ko threats in the case that White doesn't connect at B, and of course the final ladder at C must work for Black. ]
)
(;W[cg];B[dd];W[cd];B[ec];W[cc];B[jo]LB[cg:A]
C[If White extends at A, Black will play this sequence to reduce White's potential on the upper side. ]
)
(;W[ce];B[dh]TR[df]
C[If White pulls back, Black's local move can be to jump. With this shape, it is as if White had started with a small shimari, and Black had played the marked stone as a shoulder hit.]
))
(;B[dg];W[df];B[fg]
C[The master version of AlphaGo was showing us this shoulder hit and jump, even when White has a large shimari. Even as human pros are experimenting with this move, AG in the Ke Jie version has started to play differently. ]
))
(;B[pg];W[qg];B[pi];W[oh];B[qi];W[oi];B[rg];W[qf];B[rf];W[ol]LB[pg:A][ol:B]
C[If Black plays a hane at A, White will cut to make sabaki. White's final move at B puts some pressure on the Black group in the lower right, and this is good for White. ]
))
(;W[qn];B[nq];W[jq];B[pr];W[qq];B[lq];W[fq]LB[qn:A]
C[Starting with the same board position, White played at A in game 13, and this sequence followed. ]
))

