Checking

In the so-called Lucena rook ending, the defending player runs out of checks. In this position, White failed to comprehend the importance of his own pawns.

White to move

White played 46.Rc8+ and resigned after 46...Kd4 47.Kf2 d1Q 48.Rd8+ Rd5 0-1.

Convinced that White had resources in the position, I tried 46.Kf2 against Hiarcs. I reached a position that I thought should be drawn after 46...Rf8 47.Rd7 Rf7 48.Rd8 Rc7.

White to move

I played 49.f4 and managed to get my king far enough advanced that I gave up the h-pawn without worries. The engine underpromoted to a rook on d1 as it was clear that I would capture either rook or queen.