Topic summary
Left-back
Extracted from the Wikipedia article Defender (association football).
Full-back
The full-backs (the left-back and the right-back) locate the holding wide positions and up until the 1950s, the full-backs would traditionally stay in defence at all times, except on set-pieces. There is one full-back on each side of the field except in defences with fewer than four players, where there may be no full-backs and instead only centre-backs.