Resign when winning

Moves 111 to 120  

responded to , reducing the area while attacking White's connection. en deploy a sacrifice technique, gaining liberties for White's string below and allowing to cut at in sente.

Moves 121 to 122  

When Black noticed that the sacrifice resulted in his 3 stones being captured, he resigned. What he (and me, playing White) seemed to ignore is that he was still ahead. Before this local gain for White, Black was up by 15 points at least.

Sure, locally Black had been outmaneuvered.

 

Black's proper response was not to take the bait of the sacrifice but play instead. While A is big endgame, strengthening the center activates aji like B and C. Black has a clear lead.