Football pundits say that good attacking football starts with the defence.
There is no better feeling than a sliding block, or chasing after a striker and nicking the ball off their toes.
Scoring is important but your manager will be just as happy to see you stopping a goal.
Ashley Cole is the Arsenal and England left-back
Full-backs, who play on either side of the defence, have quite a varied role.
Their main job is to stop the opposition attacking in wide areas and to support the central defenders.
And the modern defender will often venture beyond the halfway line - unheard of until relatively recently.
They play an important role in supporting their team's own attack by pushing forward to supply crosses.