1v1 starting at the posts is a variation of 1v1 where the coach plays a ball out to one side and the defender from the opposite side applies pressure from behind. It's a great way for attackers to practice in back to goal situations and for defenders to work on closing down quickly.
Divide players into two lines with one line at each post. Place a goal keeper in the goal and have a supply of balls ready outside the top of the box.
Players start this drill with one hand on the post next to them. When both players are ready, play starts when the attacker moves forward, checking into space. Once the attacker's hand leaves the post the defender can chase after the attack to close the space.
The coach plays a ball out to the attacker who then tries to turn and score a goal against the defender. If the defender wins the ball, the play is dead. With that being said, another variation could be played with mni goals on the opposite end for play to continue in the event that the defender wins it.
Have players switch lines when they are done so that all players have the chance to work on offense and defense.
Defenders should be ready to close the space quickly as soon as the offensive player starts their run. The objective for the defender should be to keep the attacker's back to goal which can be achieved by applying pressure from behind.
The attackers should work on making good runs into space and trying to get around the defender to score.