The off tackle run in football is an important running play in a team's offense where a running back carries the ball running in a lane opened due to an offensive tackle's blocking. There are variations of off tackle runs, which have different players or number of players blocking, but the essence of the play is the same, to open a space large enough for a running back to run through.
When getting the ball the running back must wait until a space is open. That way, he ends up holding the ball behind the line of scrimmage a little longer than usual. That extra time is the off tackle run's vulnerability; the running back is still for a long time,O which gives the defense more time to get to the ball carrier; that way the risk of being sacked and losing yards is very big. For off tackle runs to work well, a team must have strong and skillful linemen who can open the space for the running back as quick as possible. With weak linemen, the running back gets stuck behind the line of scrimmage, with nowhere to run.
Off tackle runs are used in short yardage situations, but can lead to long runs if done correctly.