I’ve had a number of cases in games where I’ve lost before I even realised it.  This game was lost despite another 10 moves taking place after this board.

Red to move and lose

The problem here?  Division of the red pieces.  There’s no way to force the position of white’s kings to move the two red’s kings together.  If it was white’s move rather than red’s, it may be a different story.  This shows the importance of having ‘the move’.

If you can divide your opponents pieces, especially in this scenario where it’s impossible to seek the double corner, you can use your advantage to back pieces against the edge.  That’s exactly what happened above.