THE KNIGHT GOES WHERE THE QUEEN CANNOT
The queen, the rook and the bishop all move along lines out of one square. The knight does not: not one of its eight squares lies on any line of the queen, and that holds for every square of the board. This is why intervening pieces do not block a knight — between the square it leaves and the square it arrives on there is nothing to pass through.
The second thing the table shows: the rook is the only piece whose number of squares does not depend on where it stands. Seven along the file and seven along the rank come out of any one of the sixty-four squares, corner and middle alike. For the others the spread runs from 7 against 13 for the bishop to 2 against 8 for the knight.
The bishop loses the most, and not in count: a diagonal never changes the colour of a square, so half the board does not exist for it. A bishop on a light square will never stand on a dark one, however many moves it is given — and that is a property of the move, not of any one game.