(;
AB[pd][ce][pp][cq][dp][ep][eq][fp][fo][go][cd][cc][ee]
AW[cn][dq][dr][er][fq][gr][gp][hp][dc][cb][fd][bb][di]
TR[bb]
C[Black's response to White's marked play?

Source:
    Special Game Commentary
    Hashimoto vs. Tono
    Go World #1, May-June 1977, p. 41]
(;
B[ck]
C[Correct.  Black has given White territory on the top and the bottom, so if White settles the left side, the game is over.];
W[dk]
(;
B[bi];W[cl];B[bk];W[dl]
C[In the game, Black connects solidly out to his top group, and aims to drive White's unsettled group out to the center.];
B[ho]
C[The game continued ...];
W[io];B[in];W[jn];B[jo];W[ip];B[im];W[kn];B[fl]
C[And the board is dynamically balanced between thickness (Black) and territory (White), with chances for both sides.]
)
    (;
    B[dl]
    C[A mistake.];
    W[cl]
    C[Now White can settle his group, regardless.];
    B[dj]
    C[For example,];
    W[ek];B[cj];W[ej];B[ci];W[ch];B[bh];W[dh];B[bg];W[em]
    C[A nice tesuji that squeezes Black.];
    B[cm];W[bl];B[dm];W[dn];B[bm];W[bn];B[bk];W[el];B[al];W[fn]
    C[An excellent result for White.]
    )
)
    (;
    B[dk]
    C[Correct idea to split White, but the wrong point.];
    W[ck];B[cl];W[bk];B[dj];W[ci];B[cm]
    C[Forced.  Otherwise, White connects all his stones.];
    W[fi]
    LB[cp:A]
    C[And White can escape to the center.  In addition, later White can aim at A for big corner profit.]
    )
)

