(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[7.50]
DT[2018-04-14]
;B[pd]
;W[dp]
;B[pq]
;W[dd]
;B[qk]
;W[nc]
;B[pf]
;W[qc]
;B[pc]
;W[pb]
;B[qd]
;W[rb]
;B[rc]
;W[qb]
;B[fq]
;W[cn]
;B[jp]
;W[po]LB[np:A][nq:B]C[Guo Juan answer this question live on KGS on April the 15th 2018. Sadly, I (climu) made a mistake recording it and we lack the sound. Here I try to summurize Guo Juan answer in a sgf file.

We are going to explain the difference between A and B.

Let's have a look of what happen if black plays A.]
(;B[np]
;W[qq]
;B[qr]
;W[qp]
;B[rr]
;W[qm]
;B[ql]
;W[pm]
;B[ol]
;W[nn]
;B[lo]C[Guo Juan suggested such joseki here.
]
;AE[ol][ql][pm][qm][nn][lo][np][qp][qq][qr][rr]LB[np:A][nq:B]C[Back to the original situation, let's have a look at B.]
;B[nq]C[The idea with B is that it's harder for white to play R4.

So Black corner is stronger.]
;W[qq]
;B[qp]C[Black can hane here.

Let's pause here to understand why this hane in this situation will be good for black.]
;AE[pb][qb][rb][nc][pc][qc][rc][dd][pd][qd][pf][qk][cn][po][dp][jp][qp][fq][nq][pq][qq]AB[dc]
;W[de]C[Usually there is this joseki.]
;B[fc]
;W[cc]
;B[cd]C[THis hane is more of a trick plays because the result will be a little bit good for white.]
;W[dd]
;B[bc]
;W[cb]
;B[db]C[Black would answer this way and white can keep things simple.]
;W[ce]
;B[bd]
;W[be]
;B[bb]
;W[ci]C[This results is good for white because, if we compare to the usual folowing joseki:]
;B[qp]
;W[op]
;B[oq]
;W[nq]
;B[pq]
;W[np]
;B[qn]
;W[jq]LB[dg:A][lp:B]TR[cd]SQ[be][nr]C[White is better at A than B.

Indeed the square stone have been exchanged already and that will make a black approach at C9 gote for instance. Black C9 will not threaten the C13 invasion because of the square stone. On the B side, a black approach at H3 would threaten the M3 invasion as we know.

Hence, we can say that black hane at triangle was a trick play.]
;AE[bb][cb][db][bc][cc][dc][fc][bd][cd][be][ce][de][ci][qn][np][op][qp][jq][nq][oq]AW[pb][qb][rb][nc][qc][cn][po][dp]AB[pc][rc][pd][qd][pf][qk][jp][fq]LB[np:A][nq:B]C[Back to the question situation, let's see why here black can hane in the inside after playing B.]
;B[nq]
;W[qq]
;B[qp]C[Here this is strong move because if we follow the same patern...]
;W[pp]
;B[rq]
;W[qr]
;B[pr]
;W[qo]
;B[rp]
;W[ro]
;B[rr]TR[qk]C[Black already have a stone perfectly placed at R9. White ends up being heavy.

So in the first place white should not attach in the corner.]
;AE[qo][ro][pp][qp][rp][qq][rq][pr][qr][rr]
;W[ol]C[Guo Juan suggested this light move.

If black reinforce R9...]
;B[qm]
;W[no]C[White can make shape like that. White ends up running faster in the corner than when black plays O4 to start with.]
;AE[ol][qm][no][nq]LB[np:A][nq:B]C[To summurize:

A make it harder for white to run fast in the center.

B is stronger in the corner for black because white can hardly attach at R3. On the other hand, white will be able to run faster in the center.

])
(;B[nq]C[The idea with B is that it's harder for white to play R4.

So Black corner is stronger.]
;W[qq]
;B[qp]C[Black can hane here.

Let's pause here to understand why this hane in this situation will be good for black.]
;AE[pb][qb][rb][nc][pc][qc][rc][dd][pd][qd][pf][qk][cn][po][dp][jp][qp][fq][nq][pq][qq]AB[dc]
;W[de]C[Usually there is this joseki.]
;B[fc]
;W[cc]
;B[cd]C[THis hane is more of a trick plays because the result will be a little bit good for white.]
;W[dd]
;B[bc]
;W[cb]
;B[db]C[Black would answer this way and white can keep things simple.]
;W[ce]
;B[bd]
;W[be]
;B[bb]
;W[ci]C[This results is good for white because, if we compare to the usual folowing joseki:]
;B[qp]
;W[op]
;B[oq]
;W[nq]
;B[pq]
;W[np]
;B[qn]
;W[jq]LB[ce:A][np:B]TR[cd]C[White is better at A than B.

Hence, we can say that black hane at triangle was a trick play.]))
