What it is

Hash marks are short lines painted on the field at every yard, in two rows near the middle. Every play starts between or on them.

In a game

If a play ends outside the hash marks, the ball is brought back to the nearest hash mark before the next play. That is why the field looks like it has three parts: the left side, the middle and the right side.

More detail

The spacing differs by level. In college, the hash marks are wider apart than in the pros, which changes how teams plan their plays, since the field is narrower on one side.

Animated play

Blue circles are the team with the ball. X marks the other team. The yellow oval is the ball.

1. The hash marks are two rows of short lines on the field, one yard apart.
2. A play starts at the same distance from the sideline as the ball was when the last play ended, but never farther outside than the hash marks.
3. If the play ends outside them, the ball is moved in to the nearest hash mark.
4. This keeps the offense from having too little room on one side of the field.