does the marked white stone strike a familiar note?
(
;
FF[4]
GM[1]
SZ[19]
AP[Jago:Version 4.29]
AB[dd][ce][bd][fc][fe]
AW[be][bf][cf][ef][hc][bc][kc]
GN[temp]
TR[bc]
(
;
B[ad]
;
W[cc]
;
B[cd]
;
W[eb]
(
;
B[fb]
;
W[ec]
;
B[ed]
;
W[gd]
;
B[fd]
(
;
W[fa]
(
;
B[ga]
;
W[dc]
;
B[ea]
;
W[da]
;
B[ac]
;
W[ab]
;
B[bb]
;
W[ba]
C[Please do not play 'a'. In a real game 'a' is a good move, as it gaines a threat.]
LB[aa:a]
;
B[cb]
;
W[fa]
LB[aa:a]
C[Please do not play 'a'. In a real game 'a' is a good move, as it gaines a threat.]
(
;
B[hb]
;
W[ca]
;
B[aa]
C[RIGHT White has turned the corner into ko, but black has already profited from the a - b exchange. In any case, the attack on black, that white was hoping for, will not materialize. White's original clamping move at c has to be termed 'handicap style'.]
LB[fa:a][hb:b][bc:c]
)
(
;
B[ea]
C[illegal]
)
(
;
B[gb]
C[bad shape]
)
(
;
B[gc]
C[bas shape]
)
)
(
;
B[gb]
;
W[ba]
LB[fa:a]
C[The hane at a gives white life and black is in trouble.]
)
)
(
;
W[dc]
C[white mistake]
;
B[ac]
(
;
W[ab]
(
;
B[da]
;
W[ea]
;
B[bb]
;
W[ba]
;
B[cb]
C[RIGHT white should be taking black]
)
(
;
B[bb]
;
W[ba]
C[now a ko is not optimal]
)
)
(
;
W[fa]
(
;
B[gb]
;
W[ab]
;
B[da]
;
W[ea]
;
B[bb]
;
W[ba]
;
B[cb]
C[RIGHT good moves at a and b]
LB[gb:a][da:b]
)
(
;
B[ga]
C[this reverts back to the correct ko solution. Both sides have made a mistake.]
)
)
)
(
;
W[ba]
C[white mistake]
;
B[ab]
;
W[ac]
;
B[dc]
;
W[db]
;
B[bb]
;
W[cb]
;
B[ea]
C[RIGHT now white is dead]
)
)
(
;
B[dc]
;
W[db]
LB[dc:a][db:b][fb:c][ab:d][ba:e][ca:f][bb:g][ea:h]
C[because of the a - b exchange, after Bc, W can live with Wd, Be, Wf, Bg, Wh]
)
(
;
B[gc]
C[this lets white live unconditionaly.]
)
)
(
;
B[cc]
;
W[ad]
C[too easygoing]
)
(
;
B[ac]
;
W[cc]
LB[ab:a]
C[the free move at a will let white live easily.]
)
)