On a scale of billions of games, your situation would be be fairly common. The author of the video got to the conclusion by stacking multiple insanely rare occu

On a scale of billions of games, your situation would be be fairly common. The author of the video got to the conclusion by stacking multiple insanely rare occurrences - the player would need to underpromote to a bishop (the rarest promotion) and then capture and checkmate while these bishops are placed in a specific configuration. The author get into weird territory fast when fishing for the strangest game out of billions.