I haven’t play Go in a very long time but I came across this short video of a Master making a major blunder. I don’t understand Japanese but you can hear the gasps and comments about it.
What happened was the Master placed a black stone and created a cross shape. This effectively gave him 1 liberty (you always want two liberties) for survival. This is called ‘atari.’
White couldn’t believe his luck so he ‘killed’ black’s stones by taking away his 1 liberty. This might not make sense to the uninitated but it’s a very simple and elegant game. You could learn the rules in less than 10 minutes but take a lifetime to master it.
This game was played by two of the highest level masters in the Go / Weiqi / Baduk world. The sad thing is that this blunder is what that Master will be known for his entire life, not that he was 9th Dan but the ‘Self Atari 9th Dan.’
Even Masters can make mistakes, no matter how dispassionate you believe you are.