Coords: x from 0→20 (left→right), y from 0→10 (bottom→top). Top edge y=10; bottom edge y=0; middle 1–9. Dark squares are blocked (closed sites); tokens cannot enter them.
Coords: x from 0→20 (left→right), y from 0→10 (bottom→top). Top edge y=10; bottom edge y=0; middle 1–9. Dark squares are blocked (closed sites); tokens cannot enter them.