private int penaltiesInGrid() {
		int[] skips = new int[Board.SIZE];
		int penalties = 0;
		for (int i = 0; i < Board.SIZE; i += Board.SUB_BOARD_SIZE) {
			for (int j = 0; j < Board.SIZE; j += Board.SUB_BOARD_SIZE) {
				penalties += penaltiesInSubBoard(i, j, Board.SUB_BOARD_SIZE, skips);
			}
		}
		return penalties;
	}
Penalties are issues in rows, columns, and issues in sub-boards (3x3).
"Issues" mean repeated numbers.
jenetics.example/src/main/java/io/jenetics/example/sudoku/SudokuGrid.java