In my last post I mentioned that being ranked higher may help in establishing credibility. I realised that this statement was actually redundant because bluffing is per definitionem an act of make-believe, regardless of the opponent’s strength.
The following example shows that it also happens among the world’s top players.
White (Lian Xiao 7p, now 9p) has just cut off the two triangled stones, grabbing the largest endgame while, presumably, holding onto the two super important cutting stones (squared).
Black (Kim Jiseok 9p, famous for his sure-lose fuseki that he also played in this game) is losing now if he doesn’t do anything about it.
Thus he played a couple of meaningless exchanges, in order to gain byo-yomi periods and consider his options wisely.
Black reaches the conclusion that his best course of action is to create ko threats with the point-losing cut 193-198, in order to connect the vital stones with 199.
One more exchange with 201-202, to increase the value of his threat in this corner. And thus a ko was started by White’s throw-in 204 and atari 206.
Black uses the threat of 209 first, and during White’s ko threat 212, found time to maximise his threat in lower left even further before reponding 215.
Alas, after White took back 216, even the threat 217-219, inflated to its maximum value, was not enough. Black resigned shortly after.
What went wrong for Black?
Nothing, Kim Jiseok was losing all along.
Lian Xiao, however, unbeknownst to him, got bluffed.
There was never a ko!
After throwing in at 1, White could have simply played atari 3 and captured Black unconditionally with 5.
If Black insists, White squeezes and cuts up to 11. Black only has two liberties left and White wins the semeai.
Luckily for Lian Xiao, the largest ko threat Black was able to create still wasn’t enough to win the game. The groups Black was putting at stake in the (fake) ko were humongous by themselves.
In any case, Kim Jiseok’s goscar-worthy bluffing in this game was successful, and he might have won under slightly different circumstances.