Brain Teaser - How Many Knights?

Brain Teaser

In chess, a knight moves two squares in one direction and one square in another direction, ending up on the diagonally opposite corner of a 2 x 3 grid. Intervening squared can be occupied. Find the maximum number of knights which can be placed on an 8 x 8 chess board so that so that no knight threatens another knight (can move into a square occupied by one of the other knights).

What is the placement of the knights on the board?

ANSWER - Next issue