joaopedroneto wrote on Wed, May 3, 2006 08:18 AM UTC:
The basic idea is that those 3x3 central squares are shared by all board
levels, so a piece inside one of those squares can move as if it was in
any of those 3 boards. Eg, a Rook in d3 can move as it was in board A,
board B or board C.
That's why the move capabilities inside the central squares provide much
more power to any piece there.