I’ve probably played over 15,000 chess games in the last couple years. I have underpromoted (i.e., promoting a pawn to a rook, bishop, or knight) in some situations. For instance, I had messed around with the Albin Countergambit as Black a long time ago, and a knight promotion is part of the theory in some lines. But the only other time I was underpromoting was when my opponent refused to resign and I was getting 6 knights or something silly.
Finally though, recently, I had a game where underpromoting to a knight was the best move late in the game–and best of all, I actually found it! This was so cool that I had to share it. I originally made the video for a friend, but I figured I’d post it here in case you are interested (earlier in the game there is a cool sacrifice and combo too). So check out the vid, and if you have any games where you have underpromoted, share a link or pgn to the game below.