Beating Defensive Drift
Exploiting gaps in your opponent's defensive line.
"Defensive drift" is where the defenders close to the edge of a ruck or lineout move up diagonally to try to cover more of the pitch. This "drift" leaves defensive gaps, particularly close to edge of the breakdown.
As soon as the ball is released, your scrum half can pick up and attack either by going straight for the gap or stepping sideways, as if looking to get the ball wide, before changing direction and driving through the space.
This is a simple tactic to employ and an easy change to make during a game. Given that most sides have a set defensive pattern with little variation it is therefore worth checking early on in a match how the opposition defends. If they move out diagonally, try this tactic. Even if you can’t make a clean break, there is a good chance of progress.
On the other hand, if the defenders move straight up, a quick, long pass from the breakdown might be better, taking out a couple of defenders and leaving more space for the outside runners.