Crossword puzzle clue "chessboards' horizontal rows"

Chessboards' horizontal rows

One who rows, rows, rows the boat

What the black areas on horizontal rows 4, 8 and 12 represent

Numerical two-dimensional matrix where the sum of all the rows (vertical, horizontal and diagonal) is the same

Web concerns ... and based on six familiar names hidden in rows 1, 4, 12 and 15 of this puzzle grid, what the black squares in those rows symbolize

Rows of rows

Like the finest chessboards

Pieces on chessboards