(;
PL[W]
DT[1787-05-11]
TR[hd]
AB[db][dc][eb][oc][cd][ce][cf][fd][gd][hd][qd][de][ee][ff][gf][dg][dh][gg][hg][eh][ck][cl][fn][fo][gn][do][cp]
AW[fb][fc][bc][cc][ec][ed][dd][fe][ge][he][df][ef][hf][cg][ch][ci][eg][fg][fh][hh][dk][go][qo][fp][eq][iq]
C[White's response to the marked play?

Source:
Go World #22, pp. 63-64
18th century game:  Retsugen 7p (W) v. Yasui Senchi Senkaku 6p (B)]
(;
W[ig]
C[In the game, White mistakenly captures 4 stones here.];
B[gb]
C[But Black now captures the stones in the top left.  This exchange is good for Black.  After White encloses the lower right corner, all that Black has to do to stay ahead is obtain a reasonable result when invading the bottom.]
)
    (;
    W[hc]
    C[Both players missed this correct sequence.];
    B[id]
    C[Forced.];
    W[ie]
    C[An easy to overlook exquisite continuation.  This move makes bad shape, but now White saves both these stones and those at the top.

Note that Black's ladder at A does not work.]
    LB[je:A]
    )
)

