Ball (gridiron football) in the context of "College football"

A spheroid, also known as an ellipsoid of revolution or rotational ellipsoid, is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters. A spheroid has circular symmetry.

If the ellipse is rotated about its major axis, the result is a prolate spheroid, elongated like a rugby ball. The American football is similar but has a pointier end than a spheroid could. If the ellipse is rotated about its minor axis, the result is an oblate spheroid, flattened like a lentil or a plain M&M. If the generating ellipse is a circle, the result is a sphere.

American football, referred to simply as football in the United States and Canada and also known as gridiron football, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, the team with possession of the oval-shaped football, attempts to advance down the field by running with the ball or throwing it, while the defense, the team without possession of the ball, aims to stop the offense's advance and to take control of the ball for themselves. The offense must advance the ball at least ten yards in four downs or plays; if they fail, they turn over the football to the defense, but if they succeed, they are given a new set of four downs to continue the drive. Points are scored primarily by advancing the ball into the opposing team's end zone for a touchdown or kicking the ball through the opponent's goalposts for a field goal. The team with the most points at the end of the game wins. In the case of a tie after four quarters, the game enters overtime.

American football evolved in the United States, originating from the sports of soccer and rugby. The first American football game was played on November 6, 1869, between two college teams, Rutgers and Princeton, using rules based on the rules of soccer at the time; by 1875, the sport had adopted rules similar to rugby union. A set of rule changes drawn up from 1880 onward by Walter Camp, the "Father of American Football", established concepts that would define the sport, among them the snap, the line of scrimmage, eleven-player teams, and the concept of downs. Later rule changes legalized the forward pass, created the neutral zone, and specified the size and shape of the football. The modern sport is closely related to Canadian football, which evolved in parallel with and at the same time as the American game; the two sports are considered the primary variants of gridiron football.

Canadian football, or simply football, is a sport in Canada in which two teams of 12 players each compete on a field 110 yards (101 m) long and 65 yards (59 m) wide, attempting to advance a pointed oval-shaped ball into the opposing team's end zone.

Canadian and American football have shared origins and are closely related, but have some major differences. Canadian football is played with three downs, goalposts in the front of the end zone, and twelve players on each side. American football has four downs, goalposts in the back of the end zone, and eleven players on each side. Canadian football is also played on a wider and longer field, with deeper end zones.

A touchdown (abbreviated as TD) is a scoring play in gridiron football. Scoring a touchdown grants the team that scored it 6 points. Whether running, passing, returning a kickoff or punt, or recovering a turnover, a team scores a touchdown by advancing the football into the opponent's end zone. More specifically, a touchdown is when a player is in possession of the ball, any part of the ball is in the end zone they are attacking, and the player is not down.

Because of the speed at which football happens, it is often hard for an official to make the correct call based on their vantage point alone. Most professional football leagues, such as the National Football League (NFL) and the Canadian Football League (CFL), as well as some college leagues, such as the National Collegiate Athletic Association (NCAA), allow certain types of plays to be reviewed. Among these plays are touchdowns, as well as all other scoring plays, dangerous or unsportsmanlike conduct by players or staff, out-of-bounds calls, the place on the field where the official spots the ball after a play, and turnovers. Coaches can also challenge calls, provided they are made during a play eligible to be reviewed; the only exception is during periods of the game where coaches' challenges are restricted, such as the last two minutes of each half. The NFL and CFL review all scoring plays and turnovers regardless of whether the call was questionable, and therefore do not allow coaches to challenge those plays, either. The NCAA allows Division I FBS teams to review plays throughout the regular season and postseason, while Division I FCS teams can only use it during the playoffs, Division II teams only during the quarterfinals, semifinals, and championship game, and Division III teams only during the semifinals and championship game.

Spalding is an American sports equipment manufacturing company. It was founded by Albert Spalding in Chicago in 1876 as a baseball manufacturer, and is today headquartered in Bowling Green, Kentucky. It sells softballs through its subsidiary Dudley Sports. In the past, Spalding has manufactured balls for other sports, including American football, soccer, basketball, volleyball, tennis, and golf. The company invented the first basketball in 1894.

For a brief period in the 1980s, Spalding was also a designer of aftermarket automotive wheels.