(;FF[4]
CA[UTF-8]
GM[1]
GN[Demo Board]
PC[https://online-go.com/review/350673]
PB[Black]
PW[White]
OT[Error: time control missing]
RE[?]
SZ[19]
KM[6.5]
RU[Japanese]

;AB[pd]
;AB[nd]
;AB[ic]
;AB[de]
;AB[ee]
;AB[ed]
;AB[ec]
;AB[qp]
;AB[nq]
;AW[dp]
;AW[qj]
;AW[qf]
;AW[dd]
;AW[dc]
;AW[ce]
;AW[df]
;AW[cg]
;B[]LB[eb:G]LB[bc:B]LB[lc:C]LB[cd:A]LB[ef:F]LB[qh:D]LB[qm:H]LB[pp:E]C[There's many things to note about this position.

White has a wide extension with an invasion point at D. Black (on the top) has an invasion point around C. The lower left 4-4 and shimari in lower right can be considered "incomplete". And finally, White has defects in the corner around A and B (they make it so that Black can almost always get G in sente, or make the push at F much more painful).

What seems to be the most urgent (for ELF and 20-block Leela) is the upper left, playing moves such as F (first choice) or G.

The 40-block Leela however wants to settle the bottom corners, by playing E.

Why is the upper right important? I would surmise because it's multi-purpose: it worsens black's shape, help's white's corner, makes the invasion point around C more severe, and in the case of F gives influence along the left side and White's 4-4.

Invading at C is probably only good if doing so threatens an attack or pokes at weaknesses. If C just ends up being a weak group jumping out in the middle of thickness on both sides it's just a bad reduction.

Why is D not an immediate concern? Because White still has both the upper right corner and H as options. It's still fine to defend it though, and could be considered the more calm style.
]
(;W[pp]C[The aggressive AI style.]
;B[pq]
;W[qo]
;B[op]
;W[po]
;B[rp]
;W[oo]C[This move is important to prevent a Black stone here.]
(;B[ro]
;W[mp]
(;B[qm]
;W[mq]
)(;B[mq]
;W[lp]
;B[qm]
;W[lq]
))(;B[no]
;W[nn]
;B[mo]
;W[mn]
;B[lo]
;W[qq]
;B[ro]
;W[qm]
;B[qr]
;W[gq]
;B[eb]C[Black gets to come back to shape in the upper left, but White has a pretty good game.]
;W[fg]
))(;W[lc]C[What about invading directly?]
;B[ef]LB[qh:A]C[Black could actually ignore it. Black's corner might look frail but remember White's weakness at A.]
(;W[le]C[And if White persists?]
;B[dh]
;W[ch]
;B[di]
;W[nb]
(;B[pb]
;W[rd]
;B[mf]
;W[lf]
;B[mg]
;W[lg]
;B[mh]
;W[ph]
;B[lh]
;W[id]
;B[jc]
)(;B[qe]
;W[qc]
;B[rf]
;W[oc]
;B[qg]
;W[qm]
;B[fq]
(;W[hq]
)(;W[cn]
;B[dq]
)))(;W[eg]
;B[fg]
;W[eh]
;B[fh]
;W[ei]
(;B[le]
)(;B[qh]
;W[qm]
(;B[pf]
)(;B[pi]
;W[pj]
;B[oi]
;W[qc]
;B[qd]
))))(;W[ef]C[ELF and 20-block's favorite move.]
(;B[ff]C[Replying to it means White got something from nothing.]
;W[fg]
(;B[gg]
;W[eb]
)(;B[gf]
;W[gg]
;B[hf]
;W[cn]C[Nice development for White.]
))(;B[cq]C[And if Black here?]
;W[cp]
;B[dq]
(;W[ep]
;B[fr]
(;W[fl]C[Hilariously enough, this is a move.]
)(;W[id]C[Smack!]
(;B[jc]
;W[gd]
;B[fb]
;W[db]LB[gb:A]LB[qe:B]LB[ff:D]LB[dl:C]C[Black probably tenukis to B or C. White has endgame at A later. If Black tries D, White cuts!]
)(;B[hc]
;W[kd]C[Painful for Black.]
)))(;W[fq]
;B[eq]
;W[ep]
;B[fr]
;W[gq]
;B[gr]
;W[hq]C[Also fine.]
)))(;W[eb]C[Another possibility.]
;B[fb]
;W[db]LB[gc:B]LB[lc:A]C[Black can tenuki now. But White fixed their corner (lots of cash) and an invasion around A would be much more severe because of the weakness around B.]
;B[ef]C[Answering is still a good move because a White move here would be very severe.]
;W[eg]
;B[fg]
;W[eh]C[Black wants to tenuki now. Pushing seems to give away too much on the side.]
(;B[fh]
;W[fi]
(;B[gi]
;W[fj]
;B[gj]
;W[fk]
;B[bo]
;W[cp]
)(;B[ei]
;W[gi]
;B[ch]
;W[di]
;B[ej]
;W[ci]
))(;B[qh]LB[qc:B]LB[fh:A]LB[qm:C]LB[cn:D]C[White has A-D to look forward to.]
))(;W[oe]C[Suggested in Reddit thread. It's still probably a good move, but later networks seem to have moved away from the style?]
;B[od]
;W[rd]
;B[ef]
(;W[eg]
;B[fg]
;W[eh]
;B[fh]
;W[ei]
;B[og]LB[eb:B]LB[cd:A]C[Black could also play at A to see what White wants to do in the corner (might allow Black B in sente).]
)(;W[dh]LB[og:A]LB[cq:C]LB[fq:B]C[Next Black A-C are all fine choices.]
))(;W[fq]LB[ef:A]C[Also possible. Keeps all the tension. Black probably at A next.]
)(;W[qm]LB[ef:A]C[Super calm move. Fully possible. Black probably A next and try to take sente to approach/invade lower left.]
))