American football, known as football in the United States, is a team sport played between two teams of 11 players with an oval ball on a rectangular field 120 yards long and 53.3 yards wide with goalposts at either end. The team in possession of the ball (the offense) attempts to advance down the field by running with or passing the ball. In order to continue their drive, the offense must advance the ball at least 10 yards down the field in a series of four downs. If they succeed, they receive a new set of four downs to continue their drive, but if they fail, they lose control of the ball to the opposing team. The offense can score points by advancing the ball into the end zone (a touchdown) or by place or drop kicking the ball through the opponent's goalpost (a field goal), while the defense can score points by forcing an offensive turnover and advancing the ball into the offense's end zone or by tackling the ballcarrier in the offense's end zone (a safety). The team that has scored the most points by the end of the game wins.
Rex Ryan (born 1962) is an American football head coach for the New York Jets of the National Football League (NFL). After serving as an assistant coach for 22 years, Ryan attained his first head coaching job in the NFL with the Jets in 2009. He is the son of former Philadelphia Eagles and Arizona Cardinals head coach Buddy Ryan and is the fraternal twin brother of Rob Ryan, defensive coordinator for the Dallas Cowboys. Upon graduating from Southwestern Oklahoma State University, Ryan spent the next 22 years serving as an assistant coach on different teams at both the college and professional level. At the behest of their head coach Brian Billick, Ryan joined the Baltimore Ravens in 1999 and spent nine years there. In 2005 he earned the title of defensive coordinator and in 2008 became the assistant head coach. Hours after the Ravens lost to the Steelers in the 2008 playoffs, Ryan accepted a contract offer from the Jets for their vacant head coaching position. He has become well known throughout the league for his outspoken manner, boisterous attitude and success with the Jets, and his teams are highly regarded by critics for their defensive capabilities.