(;GM[1]FF[4]SZ[19]AP[SmartGo:3.0.1]CA[utf-8]
GN[RR24_2017.07.17_AlphaGo-AlphaGo-04-annotated-FINAL-intro]
PW[AlphaGo]
PB[AlphaGo]
KM[7.5]
RE[W+Resign]
RU[Chinese]ST[2]
C[AlphaGo-AlphaGo Game 4; commentary by Michael Redmond 9p

With this game I get to talk about some moves in AlphaGo's opening that remind me of the great player Go Seigen. The territory is very close throughout the game, while fighting in the center gradually escalates with trades and semeais to be calculated and discarded, and even during a final ko to kill a huge Black group, the correct variations leads to a half point difference. ]
MU[1];B[pd];W[dc];B[dq];W[pp];B[de];W[ce]
C[AlphaGo tends to play simple joseki, and rarely plays a pincer. ];B[cf]
C[Black avoids the nadare joseki. In the 2015 match against Fan Hui AlphaGo made a mistake in the nadare, giving Fan a temporary advantage, and in the Master series a new move played by AlphaGo in the nadare against Mi Yuting (game 29), turned out to be a mistake. Human pros have been studying corner sequences for centuries, and I hypothesize that complicated joseki sequences such as the nadare can give human players a good possibility of catching AlphaGo in a mistake. Maybe bad results with complicated joseki have caused AlphaGo to attach higher values to simple moves in the corner. ]
;W[cd];B[df]TR[dg]
C[This version of AlphaGo does not play the hanging connection (marked) that we saw in the Lee Sedol match, but will always connect at 9. When Black plays the solid connection, White needs to answer in the upper left, so Black will get sente to extend on the left side (see var). ]
(;W[fc];B[cl]TR[dj]
C[With the Black stone in the LL corner, this is a position where it seems natural for Black to try to control the entire side with a Chinese fuseki type extension, and few pros would play the joseki move (marked). ]
;W[nq];B[mp];W[np]
C[In the Master series AlphaGo started to play shoulder hits such as Black 13. These have become wildly popular in human play. Even as we start to experiment with this new style, AlphaGo is changing the way it continues after the shoulder hit (see var). ]
(;B[ql];W[qf];B[mo]
C[Playing away at 15 and extending at 17 both seem close to the style of play that Go Seigen was suggesting. It is fascinating to see these similarities (see var).  ]
(;W[fq]TR[mo:mp]
C[White switches to the left, attempting to reduce the value of Black's wall (marked) by splitting the lower side. ]
;B[hp];W[go]
C[White leans to the right while aiming to attack on the left (two vars added). ]
(;B[do]
C[Black protects the corner and left side, the correct direction of play. ]
;W[em]
C[White 22 is a light kikashi that connects White's stones. ];B[dn];W[ho]
C[White pushes on top to get good shape. ];B[ip];W[io];B[jp];W[lr];B[jo]
;W[im]
C[It is difficult for Black to attack White directly (see var). ]
(;B[qp];W[qo];B[po]
C[Black's plan with 31 and 33 is to reinforce the lower-side Black group (see var). ]
(;W[qq];B[rp];W[pn];B[oo];W[no];B[on];W[nn];B[om];W[pq]
C[With the tesuji of 36~40, White has split the Black groups (see var). ]
(;B[jm]
C[It is correct for Black to move out at 43, making miai of the center and the right side. ]
;W[ro];B[il];W[hl];B[ik];W[hk];B[hj];W[gj];B[hm];W[in]
C[Pulling the single stone out does not work (see var). ]
(;B[gp]
C[Having put White in damezumari with the 51-52 exchange, Black can push through here and cut (see var). ]
(;W[jn];B[gi];W[fj];B[fp];W[fi];B[hi];W[fh];B[ci];W[km]
C[Black has a small advantage in territory but a weak position in the center. Black has sente to switch to the upper right and the game is still close. ]
;B[qe];W[pf];B[nd]
C[Black can make eyes in the lower right (see var). ]
(;W[rm]
C[White 66 takes away Black's eyespace, creating potential to attack on the right and in the center. ]
;B[pi];W[mf];B[fl];W[gk]
C[Black should take away White's eye space in the upper right (see var). ]
(;B[rl];W[ph]
C[With 72, White made eyes and a strong shape on the right side. ];B[oh]
;W[qh];B[oi];W[og]
C[White's group has become strong , and now the upper side and the UR corner are miai. ]
(;B[re];W[lc];B[mh];W[le];B[mb]
C[With 77 and 81 Black takes the corner, getting a lead in territory. ];W[eq]
;B[dr];W[fo];B[eo];W[lb];B[mc];W[ki];B[hg];W[pb];B[pc];W[md]
C[Black must protect the corner (see var). ]
(;B[ob]
C[Black is about 20 points ahead in territory, so White needs to make something on the upper side while attacking Black's group in the center. ]
;W[ge];B[kh];W[nc];B[nb];W[jr];B[ir];W[cj];B[bj];W[bi]
C[White 100 and 102 is the tesuji to break into the left side. White will sacrifice one of the 2 cutting stones (see var). ]
(;B[dj];W[ch];B[di];W[dh];B[gf]
C[With 103 Black took profit on the left side. Black 107 offers to sacrifice 3 Black stones (see var). ]
(;W[he]
C[It is correct for White to attack the whole group while taking territory on the upper side. ]
;B[ff];W[li];B[bf];W[bh];B[lh];W[ji];B[ij]
C[Black can't afford to give anything away, and also is looking for a chance to counter-attack. ]
;W[ig]
C[Black seems to have a chance to cut in the center (see var). ]
(;B[ek]
C[Black takes away White's eye space while threatening to cut. ];W[ih]
C[White threatens to cut Black (2 vars added). ]
(;B[jl]TR[gm][kn]
C[With 119 Black prepares to jump out in the center and threatens cuts at the marked points (see var). ]
(;W[eg];B[hf];W[if]
C[White still threatens to cut Black (see 2 vars). ]
(;B[ed]TR[ef]
C[Black 123 tries to get a better result than simply connecting at the marked point by creating some potential to reduce White's upper side territory. The drawback is that it is not completely connected, and this becomes an issue when Black's center and right side groups are not settled yet. ]
;W[gm];B[lk];W[ko]
C[This was a chance for Black to complete the connection in the upper left (see var). ]
(;B[kp]TR[gc][fd]
C[Black 127 is a big move and threatens to cut White. Black failed to play the marked exchange first, and that became a problem for Black when White started to attack on the right side. ]
;W[ep];B[gr];W[ll];B[kl];W[lm];B[mk];W[nl]TR[fd]
C[Black's right side is in danger now, so the timing of a play at the marked point becomes difficult (see var). ]
(;B[nk]
C[Black 135 was the wrong order of moves (see the var).  ];W[ol]
C[Now White can push through at 136 safely. ];B[ml];W[kk];B[kj];W[fe];B[ef]
;W[mm]TR[nk][ol]
C[Because of the marked exchange Black cannot cut. ];B[pm];W[nm]
C[Now Black will have trouble making eyes while connecting all of its stones (see var). ]
(;B[qi];W[pk]
C[Black's connection in the center is weak (see var). ]
(;B[ok];W[lj];B[jk];W[pl];B[qm]
C[2 vars for White's move. ]
(;W[nj]
C[White 152 is a tesuji (see var). ]
(;B[oj]
C[The 152-153 exchange reduced Black's eyespace. ];W[rj];B[ri];W[qj];B[fd]
;W[gc];B[rn];W[rf];B[sj];W[sk];B[sh];W[se];B[rk]TR[rn]
C[Black's big group depends on this ko to survive. Black has gained several points with the move at 159 (marked), so the game is still close. ]
;W[si];B[gd];W[hc];B[sj];W[dp];B[cp];W[si];B[ne];W[nf];B[sj];W[dm];B[cm]
;W[si];B[be]
C[Two questions must be asked now:
Why is this a valid ko threat?
How should White answer to give Black the fewest ko threats? (4 vars added)]
(;W[db]
C[White 180 is strange looking, but it turns out to be the best move in this position when the number of ko threats is very important. ]
;B[sj];W[co];B[cn];W[si]
C[When White has played 180 in the UL corner, Black can't play the jump as a ko threat (see var). ]
(;B[bd];W[bc];B[sj];W[cq];B[bo];W[si];B[dd];W[cc];B[sj];W[cr];B[er];W[si]
;B[lo];W[kn];B[sj];W[bp]
C[If Black connects, White will get an extra ko threat in the LL corner (see var). ]
(;B[fr]TR[co]
C[Now white has only four ko threats in the corner, so Black 201 is better than playing at the marked point, which allows five ko threats. ]
;W[si];B[jh];W[ii];B[sj];W[co];B[kf];W[ni];B[mj];W[mi];B[nh]
C[Black found a good time to play 207 as a forcing move (see var). ]
(;W[ke]
C[Black's correct move is to connect on the second line (see var). ]
(;B[cp]TR[co]
C[Black 213 is a mistake in that White can gain a ko threat by taking back at the marked point later. ]
;W[si];B[je];W[jf];B[sj];W[br];B[aq];W[si];B[pj];W[qk];B[sj];W[ap];B[cs]
;W[si];B[lf];W[me];B[sj];W[bs];B[ar];W[si];B[ec];W[eb];B[sj];W[hh];B[gh]
;W[si]
(;B[jd];W[ie];B[sj];W[fg];B[gg];W[si]LB[hd:A][co:B][sc:C][sn:D]
C[Black resigns. Black has only two ko threats at A, while White has valid ko threats at B, C and D. ]
)
(;B[ie];W[id];B[sj];W[co];B[bn];W[si];B[jd];W[jc];B[sj];W[fg];B[gg];W[si]
;B[kd];W[kc];B[sj];W[sc];B[si];W[qb];B[rd];W[sd];B[qc];W[rc];B[pe];W[rq]
;B[fm];W[lq];B[lp];W[fn];B[en];W[bk];B[ck];W[aj]
C[White is going to win by the smallest margin. ]))
(;B[bn];W[si];B[je];W[jf];B[sj];W[br];B[aq];W[si];B[pj];W[qk];B[sj];W[ap]
;B[cs];W[si];B[lf];W[me];B[sj];W[bs];B[ar];W[si];B[ie];W[id];B[sj];W[hh]
;B[gh];W[si];B[jd];W[jc];B[sj];W[fg];B[gg];W[si];B[ec];W[eb];B[sj];W[sc]
C[White has run out of big ko threats, but this jump on the 1st line is big enough (2 vars). ]
(;B[qb];W[si];B[kd];W[kc];B[sj];W[bk]TR[jj][sn]
C[Both sides have one final ko threat (marked), so now Black must finish the ko. ]
;B[si];W[ck];B[fm];W[fn];B[en];W[rq];B[bl];W[dk];B[dl];W[aj];B[ej];W[lq]
;B[lp];W[ad];B[rc];W[sb];B[rd];W[sd];B[rg];W[sf];B[qn];W[sp];B[jq];W[js]
;B[is];W[kq];B[mq];W[mr];B[op];W[oq];B[jg];W[ld];B[mg];W[oe];B[od];W[ra]
;B[rb];W[sn];B[sm];W[ma];B[na];W[la];B[qg];W[pg];B[al];W[ak];B[gl];W[hn]
;B[ag];W[bg];B[qa];W[ah];B[hd];W[ei];B[pe];W[of];B[af];W[so];B[sa];W[ac]
;B[ra];W[ie];B[kk];W[sg];B[rh];W[ng];B[sl];W[mn];B[el];W[ln];B[fk];W[dg]
;B[cg];W[ee];B[ae];W[jj]
C[W+1.25 stones (2.5 pts)])
(;B[si];W[qb];B[rd];W[sd];B[qc];W[rc];B[pe];W[rq];B[qn];W[sp];B[fm];W[fn]
;B[en];W[lq];B[lp];W[bk];B[ck];W[aj];B[bl];W[cj];B[jq];W[js];B[bj];W[ak]
;B[al];W[cj];B[is];W[kq];B[bj];W[ai];B[pa];W[ra];B[la];W[ka];B[ma];W[kd]
;B[ac];W[ab];B[ad];W[bb];B[mq];W[mr];B[op];W[oq];B[rg];W[sf];B[gl];W[hn]
;B[bg];W[fk];B[el];W[ag];B[af];W[jj];B[kk];W[sn];B[sm];W[oa];B[qg];W[pg]
;B[na];W[oe];B[od];W[hd];B[of];W[ng];B[cj];W[so];B[oc];W[qa];B[oa];W[ah]
;B[oe];W[dg];B[ei];W[hm];B[sg];W[mg];B[lg];W[jg];B[sl];W[rh];B[kg];W[ee]
;B[cg];W[eh];B[ej];W[ln];B[mn]
C[W+0.25 stones (1.5 points)])))
(;W[si];B[ke];W[jd];B[kd];W[ld];B[id];W[hd];B[jc];W[ic];B[je];W[ie];B[kb]
;W[la];B[ib]LB[rh:A]
C[Now White must fight the ko at A to connect. This is bad for White. ]))
(;B[co];W[fr];B[fs];W[ds];B[gq];W[br];B[ap];W[aq];B[ao];W[cs];B[as]
C[White had 5 ko threats after Black answered, while in the game White had only 4. ]
))
(;B[kf];W[sj];B[ke];W[jd];B[kd];W[ld];B[id];W[hd];B[jc];W[ic];B[je];W[ie]
;B[kb];W[la]
C[White can still connect on the top (see var). ]
(;B[ib];W[ni];B[nh];W[rh];B[bc];W[bd];B[ad];W[bb];B[ab];W[ba];B[lf];W[me]
;B[ec];W[eb];B[fa];W[hb];B[ha];W[ga];B[gb];W[fb];B[ga];W[cc];B[ca];W[ac]
C[In this ko, White has several local ko threats, while Black has almost none. ]
)
(;B[rh];W[jb]
C[White is connected.])))
(;W[bd];B[ec];W[eb];B[db];W[cb];B[bc];W[cc];B[fb];W[da];B[ea];W[fa]LB[bd:A]
C[This var shows Black's ko threats in the UL corner when White answers at A. Black has 5 ko threats, while Black had only 3 in the game variation. ]
)
(;W[ec];B[sj];W[co];B[cn];W[si];B[kf]TR[bc]
C[In this var Black 6 becomes a ko threat ( 2 vars). ]
(;W[sj];B[ke];W[jd];B[kd];W[ld];B[id];W[hd];B[jc];W[ic];B[je];W[ie];B[kb]
;W[la];B[ib];W[ni];B[nh];W[rh];B[bc];W[bd];B[ad];W[cb];B[bb];W[dd];B[lf]
;W[me];B[ba];W[jg];B[hb];W[gb];B[ha];W[ka];B[jb];W[ja];B[ee]LB[ec:A][kf:B]
C[White dies. White's move at A was badly placed when White ignored the Black ko threat at B, starting this fight. ]
)
(;W[ni];B[mj];W[mi];B[nh];W[ke];B[sj];W[cq];B[bo];W[si];B[lf];W[me];B[sj]
LB[lg:A][bc:B]
C[In thus var Black has a potential eye at A and will be able to use moves like B as ko threats next. ]
))
(;W[cb];B[bc];W[bd];B[ad];W[cc];B[ec];W[eb]
C[Black's ko threats in the UL corner are shown in this var. Black had 3 ko threats, which is the same as the actual game, but White has lost some points so this is inferior to the game for White. ]
)
(;W[sj];B[ec];W[eb];B[cb];W[db];B[cc];W[dd];B[bd];W[bb];B[bc];W[ca];B[ba]
;W[aa];B[ac];W[da];B[ab]
C[If White finishes the ko, Black can live with this sequence. White cannot connect because of damezumari. ]
))
(;B[mj];W[mi];B[ni];W[pj];B[oj];W[rj];B[ri];W[rk];B[rn];W[rf]LB[rk:A]
C[When White can cut black with the bamboo joint at A, Black  cannot save the big group in the center after White 10. ]
))
(;W[rj];B[ri];W[qj];B[pj];W[qk];B[rn];W[rf];B[sh];W[se];B[sj];W[sk];B[rk]
LB[oj:A][kf:B]
C[The difference between this var and the actual game is that Black has an eye at A, and Black's ko threats such as B will be more effective. ]
))
(;B[rj];W[lj];B[jk];W[nj];B[oj];W[ni];B[ok];W[nh]
C[White captures 3 stones to win. ]))
(;B[qj];W[pk];B[ok];W[pl];B[qm];W[nj];B[oj];W[qi];B[pj];W[rj];B[qk];W[rn]
C[White wins. ]))
(;B[ml];W[nm]
(;B[nk];W[fe];B[ef];W[lo];B[ol];W[rj];B[qj]
C[This is very close. ])
(;B[fd]TR[mm]
C[Black threatens to cut at the marked point. ];W[kk];B[kj];W[lj];B[jk];W[nj]
C[White can cut off the Black group on the right side (two vars). ]
(;B[ec];W[mm]
C[Black is in trouble on the right side. ])
(;B[mm];W[mn];B[ln];W[kn];B[lo];W[fm]
C[The right side Black group is in trouble already. White threatens to live in the center. ]
(;B[ck];W[gl];B[en];W[hh];B[gh];W[gc];B[ef];W[be];B[fn];W[gn]LB[fe:A]
C[Black can get a seki by playing at A, but the Black group on the right side will die. ]
)
(;B[ec];W[mq];B[lp];W[en];B[ck];W[gl]
C[Black is in trouble on the right side. ])))))
(;B[fd];W[gc]TR[gc][fd]
C[Black should play the marked exchange ( 2 vars) ]
(;B[ml];W[kp]
C[White cuts of 2 Black stones to take the lead (2 vars for Black's next move).]
(;B[jq];W[mj];B[nl];W[lm];B[ll];W[rj]
C[White wins. ])
(;B[mi];W[hr]
C[White's attachment works (2 vars for Black's move)]
(;B[is];W[iq]
C[(2 vars)]
(;B[hq];W[jq];B[gr];W[ep];B[gq];W[fr];B[hs];W[fs]
C[White wins.])
(;B[jq];W[hq];B[kr];W[ep];B[kq];W[lq];B[js];W[ls]
C[White wins]))
(;B[gr];W[is];B[gq];W[lm];B[kk];W[be]
C[White wins])))
(;B[kp];W[ll];B[kl];W[lm];B[mk];W[nl];B[ml];W[nm];B[lo];W[kn];B[nk];W[fm]
;B[ol]
C[This is very close. ])))
(;B[gm];W[hh];B[gh];W[ef];B[fe];W[ee];B[kn];W[gg];B[fg];W[fd]
(;B[gg];W[ln];B[ko];W[kl];B[fn];W[jj];B[gn];W[qj]
C[Black wins the semeai but is behind in territory and in trouble on the right. ]
)
(;B[kl];W[gg]
C[White wins. ]))
(;B[ef];W[gm];B[lk];W[ko];B[kp];W[ll];B[kl];W[lm];B[mk];W[lo];B[nl];W[is]
;B[hr];W[lp]
C[White has a small lead. ]))
(;W[gg];B[lk]
(;W[hh];B[fg];W[gh];B[eh]
C[Black escapes in the center and wins on the left side. This is good for Black. ]
)
(;W[eg];B[hf];W[if];B[dd];W[cc];B[hh];W[ef];B[fe];W[ee];B[fd];W[ed];B[gc]
;W[id];B[fb];W[ec];B[gd]
C[Black has gained more on the upper side than White has on the left. This is good for Black. ]
)))
(;B[gm];W[eg];B[ef];W[gg];B[hf];W[hh];B[gh];W[fg]LB[gm:A]
C[When Black cuts White off with A, White can cut the Black group to capture the Black stones in the center. ]
)
(;B[hf];W[gm]
C[Two vars for Black's next move. ]
(;B[if];W[hh];B[gh];W[lk]
C[Black cannot escape in the center. ])
(;B[kl];W[ll];B[lk];W[kk];B[jl];W[lm];B[mk];W[if];B[kj];W[ko];B[kp];W[nl]
;B[ml];W[nm]
C[Does Black attack or defend? (two vars]
(;B[nk];W[lo];B[ng];W[nf];B[ol];W[is];B[hr];W[qi]
C[White has a small lead. ])
(;B[mm];W[mn];B[ln];W[kn];B[lo];W[lj];B[jk];W[nj];B[fn];W[hn];B[fm];W[hh]
;B[gh];W[fe];B[ef];W[eh]
C[White can get a seki in the big semeai, and Black is in trouble on the right, so this is good for White. ]
))))
(;B[ih];W[jh];B[jg];W[if];B[kl];W[ll];B[lk];W[lm];B[mk];W[kg];B[ek];W[eg]
;B[fe];W[fm];B[jl];W[ko];B[kp];W[nm];B[nl];W[qi]
C[White has a small lead. ]))
(;W[ff]
C[Does Black try to save the 3 stones? (two vars for Black's move)]
(;B[he]
C[It is best for Black to discard the 3 stones. ];W[gg];B[hf];W[fe];B[bh]
;W[bg];B[ai];W[bf];B[kd];W[ld];B[hc]
C[Sacrificing three stones, Black has gained territory on the left and upper sides. This is good for Black. ]
)
(;B[eg];W[eh];B[fg];W[gh];B[fe];W[hh];B[gd];W[he];B[fd];W[jh];B[ec];W[eb]
;B[ed];W[fb];B[gg];W[ig];B[hd];W[ie];B[bf];W[bh];B[ef];W[mi]
C[Black can save the group on the left, but loses too much in the center, and this is bad for Black. ]
)))
(;B[bh];W[bk];B[ai];W[ck]
C[While Black is alive on the side, White has gained territory by breaking into the left side. ]
))
(;B[ge];W[ob];B[nc];W[rc]
C[This is bad for Black. ]))
(;B[kc];W[qc]
C[White can scoop out the corner. ]))
(;B[qh]
(;W[rl];B[mh]
C[By attacking White, Black can plan to strengthen the center and gain territory on the upper side. ]
)
(;W[oh];B[nj]
C[Black's group is stronger than White's on the right side. ])))
(;W[qi];B[qn];W[rn];B[rm];W[qm];B[pm]
C[Black is alive in the lower right, while White's side group is not settled yet, so this is good for Black. ]
))
(;W[fp];B[fo];W[eo];B[fn];W[en];B[gn]
C[Black captures 5 White stones. ]))
(;B[gm];W[ij];B[hi];W[fl];B[fn];W[jn]
C[Black is in trouble in the center and the lower side, so this fight favors White. ]
))
(;B[ro];W[jn];B[gq];W[fr];B[gr];W[ep];B[dp];W[gp];B[kn];W[km];B[ln];W[lm]
;B[kq];W[ir];B[kr];W[lq];B[lp];W[hs];B[iq];W[gs];B[jr];W[nc]LB[ro:A][jn:B]
C[When Black takes territory on the right with A, White can surround Black on the lower side with B. White gets a strong shape on the outside while attacking Black's side group, and this is good for White. ]
))
(;W[ro]
C[Black now has a choice of living in the corner of squeezing from the outside (2 vars). ]
(;B[mq];W[mr];B[pq];W[op];B[rq];W[pn];B[or];W[nr];B[qr];W[nm];B[km];W[pk]
C[Black lives in the corner, but since White takes the initiative in the  fight outside, I would not choose this var for Black. ]
)
(;B[pn];W[pq];B[rp];W[rm];B[qm];W[rn];B[rl];W[qq];B[ek];W[jn];B[qh]
C[Giving the corner to White, Black builds an outside wall. This var is good for Black. ]
)))
(;B[gp];W[fp];B[fo];W[eo];B[fn];W[en];B[in];W[dp];B[cp];W[ep];B[cq];W[cm]
;B[dm];W[dl];B[bm];W[ck];B[bl];W[dk]LB[gp:A][fo:B]
C[When Black pushes through to cut with A and B, White can make good shape on the left side with this sequence. ]
))
(;B[gp];W[fp];B[fo];W[dp];B[cp];W[do]LB[fn:A][cq:B]
C[A and and B are miai. This is good for White. ])
(;B[ho];W[dp];B[cp];W[co];B[cq];W[do]LB[go:A]
C[The stone at A gives White a connected shape. Since Black must live in the corner, it will be easy for White to settle this group. ]
))
(;W[lr];B[ip]
C[The usual shape for White is to slide on the 2nd line, after which Black makes a loose connection the the left. Black controls the center and has a big moyo, so this looks good for Black. ]
))
(;B[mn]LB[mp:A][mo:B]
C[In the Master series, AlphaGo almost always continued with a one-space jump. While Black A resembles the shoulder hits suggested by Go Seigen, this jump does not. Go Seigen would want us to play away, or extend at B for the local move. ]
))
(;W[cn];B[ec];W[eb];B[fb];W[ed];B[fc];W[dd];B[ge];W[db];B[ck]LB[fb:A][ge:B]
C[Black's hane at A and the keima at B are moves that were suggested by the great player Go Seigen in his commentaries of the '21st century fuseki', after which they started showing up in pro games. I have heard that this same sequence in the UL corner has been shown by AlphaGo as it's intended follow-up if White plays away from the UL corner. ]
))

