So, What Shape is a Football?
The gridiron football is shaped like a prolate spheroid. It has pointed ends and it’s slightly longer than it is wide. It has an equatorial circumference between 21 and 21 1/4 inches. The ball must be inflated to 12 1/2 to 13 1/2 pounds per square inch (PSI) pressure per square inch.
A football consists of four panels sewn together with at least four rows of stitching. The laces are located on the two longer panels, which lie opposite each other on the ball and run from one end to the other along the seam where it’s sewn together.
It is a prolate spheroid
The prolate spheroid is a geometric shape that is formed by rotating an ellipse (a slanted circle) around its minor axis, creating a three-dimensional shape that looks like a football. The ends of the spheroid are circular and the middle is oblong, while the entire object remains symmetrical. This description is also befitting of an American football and, thus, the prolate spheroid best describes what shape it takes on.
It is an ellipsoid
You may think a football is round, but it doesn’t quite meet the criteria. An ellipsoid is a three-dimensional geometric shape where the x-axis, y-axis, and z-axis are not of the same length. The football has two points at both ends that are slightly wider than its middle.
Ellipsoids are used in many practical applications such as GPS receivers, transmission lines for radio telescopes (to improve their sensitivity), supercomputers, and even some high-end cars like Ferrari. The term “ellipsoid” can also refer to a surface that looks like an ellipse when viewed from one direction.
It is also known as an oval in inflatable balls and leather balls
The exterior of the ball
The exterior of the ball is made of four panels that are stitched together with two black stripes that run across the entire ball
According to the NFL‘s official rulebook, a regulation football is:
- Made of four panels.
- Made of leather or an acceptable substitute if it’s not made of leather.
- Put together with pebbles on the panels, in the shape of small bumps that form the pattern for gripping.
- Punctured at two ends with an air valve, to control how inflated it is.
The ball should be inflated to 13 pounds per square inch (psi) and weigh 14-15 ounces.
A football is a long, narrow, prolate spheroid (an oblong sphere). The length of a football is roughly its major axis, and its width is its minor axis.
The shape has changed much since the dawn of the game in the mid-19th century. American Footballs have evolved from pork bladders to synthetic materials; their size was more standardized in 1913 to a weight between 14-15 oz. and a length of 11-11.5 inches (279-292 mm), with a maximum circumference at the center being 73-76 cm (29-30 in).
In games, the football’s width is roughly its major axis, and its length is roughly its minor axis. It’s important to note that across all sports math [sphere/ellipsoid] calculations apply only when an object becomes spherical or ellipsoidal on two or more axes, not just one single axis.
What is the geometric shape of American football?
The official shape of American football is a geometric shape called a prolate spheroid. Also known as an oblate spheroid, this shape is a ball that’s squished at both ends; if you were to look at it from the top or bottom, you’d see it bulging out in the middle and tapering down on either side.
Although many footballs look like they have more than four panels when inflated, sports balls manufactured today are actually made of four panels that are stitched together. In the case of an American football, two black stripes run across its entire width to help players and referees see the ball when it’s in motion during a game.
What is the history of the shape of American football?
You are correct: the shape of an American football is a prolate spheroid, similar to an egg or rugby ball. (The word “spheroid” means a shape similar to that of a sphere, but not quite. Both rugby balls and footballs are oblong in terms of their dimensions—therefore, they are spheroids rather than spheres.)
The exact dimensions of the football have been standardized since 1887, at which time the rules for the game were also codified. Before then, there was no standard ball size or shape. There were many different types of balls used through college and professional leagues; they could be made from leather, rubber, or cloth and could have laces or not—the only thing that was consistent across early teams was that they were all roughly oval-shaped.
Since its invention (around 1876), the shape of the football has changed several times. Early iterations could vary greatly: some were perfectly round like a baseball, while some looked more like watermelons than anything resembling what we now consider a football to look like.
The first footballs were simply soccer balls whose laces had been removed—these days, American footballs are much longer from end to end than soccer balls (and their surface is completely smooth with no laces).
Is this shape helps to play?
The ball shape is a relevant topic in sport and includes the ball’s size, material, design, and pressure. The ball must be spherical to play football, but the shape of the ball can impact play.
In throwing or receiving a ball there will be air resistance on a long spiral pass. A properly shaped football has a number of long-range benefits as well.
When passing, players try to spin it from laces over their index finger, which is called spiral passes. The purpose is to get more distance for the thrower by increasing air resistance and making sure that laces are not facing forward when thrown. This helps with accuracy because there will be less wobbling through the air without having laces in the way for the receiver’s hands to catch with ease.
The arch of a kick also depends on how much spin is put on the ball so that it can travel further through its parabolic trajectory; less spin means that it won’t travel as far or as fast through the air resulting in shorter field goals or punts.
Kicking requires more technique and skill than throwing because they use different parts of their body. For example, quarterbacks use their upper bodies while kickers primarily utilize their legs to make contact with the ball at launch (although some may also use their arms).