Stopping the 4 move checkmate

I, like so many new players, suffered the indignity of losing to the 4 move checkmate early in my career. It happened in a school chess competition, and I was so shocked and annoyed, that I spent the next class drawing a chess board in the back of an exercise book, and then moving the pieces using pencil and eraser until I worked out what had happened.
Fortunately technology is now sufficiently advanced that we have computers that do this for us. And the theory of the 4 move checkmate has moved forward as well, with a strong GM demonstrating the correct defence when confronted with the opening.


Carlsen,Magnus (2882) - Dominguez Perez,Leinier (2763) [C20]
Saint Louis Blitz 2019 Saint Louis USA (7.3), 13.08.2019