Knight + Bishop Mate
All of us class players dread the possibility of getting the better side of a Knight and Bishop vs a lone King ending. What humiliation to not be able to win with two pieces! But, it is not easy at all--especially because the stronger side only has 50 moves to get it right and with perfect defense it can easily take 30 moves to complete.
After several years of hit or miss attempts to figure out this mate, a chess.com friend recently pointed me to this video by Majnu2006 on YouTube that gives a very easy to remember (and well explained) "triangles" technique.
Here is my second attempt to follow the technique. (In my first attempt I blundered after 29 moves and allowed the king to escape his cage!)