Back row, 10 pieces can be places (middle 10, leaving 2 spaces on each side.) Next to back row, 8 pieces can be places (middle 8, leaving 4 spaces on each side) next row, 6 pieces next row, 4 pieces front row - 2 pieces
So your front row, and the front row of your opponent across from you has 4 empty spaces - kind of like current.
So each of the 4 sides has the same amount of pieces, look like pyramids, and has about the same amount of space from their opponents.