(;
AB[ld][md][nd][qd][pe][ci][cl][pl][dq][fq][iq][pq][er][gr][fs]
AW[pb][dc][mc][oc][qc][cf][do][qo][ep][eq][gp][cq][dr]
PL[W]
C[White's response to the marked play?

Source:
    Go World #22, pp. 45-47
    "The Great Joseki Debate",
    Honda Kunihisa 9P]
TR[pl]
(;
W[om]
C[The mistaken idea behind this shoulder hit is to lean on the middle right stone in order to build up strength against the lower right corner.];
B[ol]
C[The problem is that Black is happy to push up here to combine with the wall above to form a big moyo.];
W[nm];B[nl];W[mm];B[ml];W[nq]
C[White can continue the plan by pincering here, but ...];
B[qp]
C[... Black's corner is flexible.];
W[po]
C[For example, if White stands up, ...];
B[ro];W[rn];B[rp]
C[... Black easily makes life in the corner.  White's plan fails.

Of course, White can attack the corner in other ways, but the result will still be insufficient to justify giving Black the big solid moyo.]
)
    (;
    W[op]
    C[White's shoulder hit is in the right direction, but ...];
    B[pp]
    C[... Black will follow the push and cut joseki.];
    W[po];B[oo];W[pm]
    C[This attachment tesuji is the correct continuation for White, who is now threatening the "driving tesuji" starting with A, then Black B, then White C.]
    LB[no:A][on:B][om:C];
    B[no]
    C[So Black defends.];
    W[om]
    (;
    B[ql]
    LB[mq:A][nq:B]
    C[Normally, Black would continue with A, in order to defend against B.

But with the marked stones to the left to defend the right side, Black has time to block here on the right.  One possible sequence follows.]
    TR[fq][iq][er][gr][fs];
    W[qm];B[rp];W[ol];B[pj];W[ok];B[pi]
    C[Black is satisfied with having played on both the right and lower sides, while White's group is weak.]
    )
        (;
        B[mq]
        C[If Black follows joseki, ...];
        W[ql]
        C[... White hanes here for a huge success.  White's group has a flexible shape, and Black's wall above has less potential.]
        )
    )
    (;
    W[oo]
    C[Correct.  This jump balances treating the lower side lightly, while keeping Black from building a big moyo above.

The variations are endless, but the following sequence gives the general theme.];
    B[np]
    C[Usual.];
    W[no];B[mp];W[mo]
    C[White pushes a couple times to build up strength.];
    B[lp]
    C[Normally, forcing your opponent along the 4th line is bad, but ...];
    W[pj]
    TR[iq]
    LB[qj:A]
    C[... now White can invade the right side here or at A.

Also note that because Black's marked stone is low, Black's lower area is not efficient.

Again, the variations are numerous, but what follows is just one possible sequence.];
    B[nl];W[lo];B[nj];W[ql];B[qm];W[rl];B[pk];W[qj]
    C[Black does not have a very effective attack against either group.]
    )
)

