Input (grade 10): Today, straight rail play is relatively uncommon in the U.S. but retains popularity in Europe, where it is considered a fine practice game for both balkline and three-cushion billiards.
Output (grade 6): Today, straight rail play is not very common in the U.S. but it still popular in Europe, where it is thought to be a good practice game for balkline and three-cushion billiards.