When the King is checked, or any valuable Piece in danger from the attack of an enemy, you are said to interpose a man when you play it between the attacked and attacking Piece.

Modern commentators consider Staunton's understanding of positional play to have been far ahead of his contemporaries'. In 1858 attempts were made to organise a match between Staunton and Morphy but they failed. Staunton has been a controversial figure since his own time and his chess writings could be spiteful.