The mistake itself was subtle. So subtle that it was hard to find, excitement rushed through Anna's head and with the time ticking slowly down to zero. However, any decent player who had more time to think would be able to find it, probably even taking advantage of everything here.
It all started when Bu Xiangzhi threatened her knight. It was just a one-move threat, something that could be swatted easily by moving away that piece. Now, the problem, though, was where she would put that piece. This was where the mistake happened.
The best way to do this was for Anna to retreat her knight. It was a strategic move to reinforce the pawns on the back as well, and it gave room for the rook to breathe.
However, Anna, who had been pushing forward for a while, got stuck in the mindset that she could only move forward here. Without even blinking, she let her knight jump toward the B7 square, which, unluckily enough, also blocked the rook on the A7 square next to it.
