Then I couldn’t believe my eyes. The white player run out of the 30 seconds byoyomi and the Black won.
If you still dont see the situation, see the tsume program below. This is three move checkmate. R1500 level player should see this in less than 20 seconds.
The first move of G*8b does not work. the King will escape to 9c. One of the basic rule of tsume is to block the King’s escape route. Therefore..
G*9c – Nx9c – G*8b. This is a simple three move checkmate.
Maybe the white’s computer have simply frozen. But if he really did not see this simple three move tsume, then his further practice on tsume problems will probably increaese his win rate a lot.