In the modern game, full-backs are expected to do more than just mark their winger, cover for the centre back and call the line - now they have responsibilities in the attacking third of the pitch.
Dynamic full-backs such as Barcelona's Jordi Alba and PSG's Daniel Alvez are the perfect example of menacing raiders from deep.
More after the break
During his playing days at Ipswich Town, former Scotland gaffer George Burley posed an threat to the opposition with his forays from right back.
In this video the Scotsman explains the tactical acumen and movement a full-back needs to leave his defensive post and bomb forward.