What it is

A tackle for loss, or TFL, is a tackle of a ball carrier behind the line of scrimmage, so the offense loses yards.

In a game

It puts the offense in a difficult spot, because the next down will need more yards. A string of them can force a punt.

More detail

A tackle for loss is also called a stuff. The defense gets credit for a TFL only when the ball carrier has the ball behind the line when tackled, not for sacks, which are a separate stat.

Animated diagram

1. The offense runs the ball, and a defensive lineman gets past his blocker.
2. He reaches the runner before the line of scrimmage.
3. The runner is tackled behind the line, so the offense loses yards.