American football

American football
Mass Communication Specialist 2nd Class Michael A. Lantron, USN · Public domain · source
Name	American football
First	19th century
Contact	Full contact
Team	11 per side
Venue	Stadium

American football is a team sport played between two squads of eleven players on a rectangular field with goalposts at each end. Originating in 19th‑century Yale University and Harvard University contests and influenced by Rugby football and Association football, the game evolved through rule changes promoted by figures such as Walter Camp and competitions organized by institutions like the Intercollegiate Football Association. Modern professionalization was driven by organizations including the National Football League and the Canadian Football League, with major cultural events such as the Super Bowl becoming national spectacles.

History

Early organized play began with matches among northeastern colleges such as Princeton University, Rutgers University, Columbia University, and Brown University during the 1860s and 1870s. Influential coaches and administrators—Walter Camp, John Heisman, Pop Warner—shaped innovations like the line of scrimmage, downs system, and legal forward pass, while rule committees convened at venues including Polo Grounds and Yale Field. Collegiate rivalries such as Harvard–Yale football rivalry and contests like the Rose Bowl Game popularized the sport. Professionalization progressed through regional circuits, the founding of the American Professional Football Association (later National Football League) and rival leagues including the American Football League (1960–1969), with franchise movements involving cities such as Green Bay, Chicago, Canton, Cleveland, and Los Angeles. Labor developments featured the National Football League Players Association and collective bargaining agreements; significant legal and commercial milestones involved entities like the National Collegiate Athletic Association and broadcasters including CBS Sports, NBC Sports, and ESPN.

Rules and gameplay

Games are officiated under rulebooks produced by governing bodies such as the National Football League Competition Committee and collegiate rules committees affiliated with the National Collegiate Athletic Association. Play is divided into timed periods (quarters) and involves a series of plays starting with a snap from the line of scrimmage; offensive objectives include touchdowns and field goals, while defenses aim for turnovers and punts. Scoring events—touchdown, extra point, two‑point conversion, field goal, safety—are codified in rulebooks overseen by organizations like the Football Rules Committee. Officials such as the referee, umpire, head linesman, line judge, back judge, side judge, and field judge enforce penalties for infractions including holding, pass interference, and roughing the passer. Game strategy incorporates clock management, timeouts, and situational play calls influenced by metrics and analytics produced by teams including New England Patriots and Seattle Seahawks.

Positions and roles

Team rosters distinguish between offense, defense, and special teams. Offensive units include positions such as quarterback, running back, fullback, wide receiver, tight end, center, offensive guard, and offensive tackle; notable players in these roles have included Tom Brady, Jim Brown, Emmitt Smith, Jerry Rice, Rob Gronkowski, Anthony Munoz. Defensive roles comprise defensive end, defensive tackle, outside linebacker, inside linebacker, cornerback, and safety, with exemplars like Lawrence Taylor, Reggie White, Ray Lewis, Deion Sanders, Ed Reed. Special teams feature placekicker, punter, long snapper, and return specialist, with figures like Adam Vinatieri, Ray Guy, and Devin Hester. Coaching staffs often include a head coach, offensive coordinator, defensive coordinator, position coaches, and strength and conditioning coaches; prominent coaches include Vince Lombardi, Bill Belichick, Nick Saban, Paul Brown, and Bill Walsh.

Equipment and field

Players wear protective equipment regulated by standard bodies such as the National Operating Committee on Standards for Athletic Equipment (historically) and manufacturers like Riddell and Schutt Sports. Mandatory gear includes helmet with facemask, shoulder pads, thigh and knee pads, cleated footwear, and gloves; helmet safety improvements followed research by institutions including Harvard Medical School and University of Pennsylvania. The playing surface is a rectangular field 100 yards between goal lines with end zones and hash marks; notable venues include Lambeau Field, MetLife Stadium, Soldier Field, and Rose Bowl Stadium. Goalposts and field dimensions differ slightly between organizing bodies such as the National Football League and Canadian Football League.

Leagues and competitions

At the professional level the National Football League is the largest organization, staging yearly playoffs culminating in the Super Bowl and featuring franchises like the Pittsburgh Steelers, Dallas Cowboys, Kansas City Chiefs, and San Francisco 49ers. Other professional leagues have included the Canadian Football League, the Alliance of American Football, and historical entities like the All-America Football Conference. Collegiate competition is organized by the National Collegiate Athletic Association with conferences such as the Big Ten Conference, Southeastern Conference, Atlantic Coast Conference, and Pac-12 Conference; postseason bowls include the Rose Bowl, Sugar Bowl, Orange Bowl, and the College Football Playoff era culminating in a national championship. International competitions and development leagues have involved organizations like International Federation of American Football and teams from Mexico, Japan, and Germany.

Strategy and tactics

Offensive schemes range from pro-style formations, spread offense, West Coast offense, and option-based attacks; innovators include Bill Walsh (West Coast) and Paul Johnson (option). Defensive systems vary among 4–3, 3–4, nickel, and dime packages, with coordinators such as Bill Belichick and Buddy Ryan known for scheming and blitz design. Play calling leverages personnel packages, motion, play action, screen passes, and RPOs (run‑pass options), while analytics groups and front offices—exemplified by Bill Parcells‑era practices and modern analytics teams—use data from scouting combines and game film to inform draft strategy and roster construction. Special teams tactics include onside kicks, fake punts, and directional kicking; situational strategy emphasizes fourth‑down decisions, two‑point conversion calculus, and clock management.

Safety and health considerations

Player safety is governed by rules and protocols instituted by organizations such as the National Football League Players Association, medical advisory panels from institutions like Mayo Clinic, and concussion research from Boston University and University of Pittsburgh. Topics include concussion diagnosis, chronic traumatic encephalopathy studies associated with researchers including Ann McKee, protocols for return to play, equipment certification, and rule changes addressing helmet-to-helmet contact and targeting penalties. Strength and conditioning, heat illness prevention, and cardiac screening are managed by team medical staffs and organizations such as the American College of Sports Medicine in collaboration with team physicians and athletic trainers.

Category:Team sports