Board 1 has 6 safe squares. Board 2 has 0 safe squares. Board 3 has 2 safe squares. Board 4 has 0 safe squares. Board 5 has 16 safe squares. Board 6 has 0 safe squares. Board 7 has 2 safe squares. Board 8 has 5988 safe squares. Board 9 has 1000000 safe squares. Board 10 has 989856 safe squares. Board 11 has 731193 safe squares. Board 12 has 6733 safe squares. Board 13 has 27910 safe squares.