endgame is the best game
Over the years, I have told students that Chernev’s Practical Chess Endings is the book that has won the most games for me.
If I am working with a student who has good potential, I start with basic ending principles.
Yes, endings may be the most important aspect of chess.
So this is an example of an ending I played like 20 years ago that sticks with me. It utilizes understanding imbalances, passed pawns and sacrificing for a win. There are some subtle parts to look at but it's a pretty good idea of how studying endgames can be of benefit.