Man-to-man marking, or man marking, is a defensive strategy used in association football, where defenders are assigned a specific opposition player to mark rather than covering an area of the pitch. The alternative to man-to-man marking is zonal marking.
The idea of man-to-man marking was perfected by the Italian teams of the 1960s and 1970s. Teams such as Inter Milan and AC Milan used it in their so-called catenaccio formation. This consisted of four man markers with a sweeper playing behind them. This brought much success to these teams and soon these tactics became popular throughout the world of football. However, this tight marking was often at the expense of the spectacle of the game itself.
The strategy is one that has been dying out in football over the past decade or so despite Greece's success with it in the 2004 European Championships.
Modern defensive formations use a mixture of both man-to-man and zonal marking e.g. 3-5-2 formation (which defensively becomes a 5-3-2). This means 5 defenders: 2 stoppers marking man-to-man, 1 sweeper (sweepers always mark by zone), and 2 wingbacks playing almost like end-to-end side midfielders.