Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. István Szekér (born 25 December 1970 in Várpalota) is a Hungarian football player. Within the sport of association football, a defender is an outfield player whose primary role is to prevent the opposition from attacking. There are four types of defender: centre back, sweeper, full back, and wing back. The centre back and the full back positions are essential in most modern formations. The sweeper and wing back roles are more specialized for certain formations.