The Evolution of the Football Itself

By 4Football Staff · October 4, 2026 · 10 min read

The football started out nearly round and became a slim, laced, hand-stitched leather ball built for the forward pass. Here is how the shape, materials and rules around the ball changed.

Every football game revolves around an object that most fans never think about. It is small enough to carry under one arm, light enough to throw sixty yards, and oddly shaped enough to bounce in directions nobody can predict. It was not designed all at once. The ball you see in a stadium today is the result of well over a century of adjustments, most of them prompted by changes in how the game was played.

A football does not look like the ball used in soccer, and it does not look exactly like the ball used in rugby. It is a pointed oval, built from leather panels, tightened with laces, and inflated to a pressure the rulebook specifies. Each of those features has a history and a reason.

This article traces how the ball changed, what the official versions look like at different levels, why the laces are still there, and how weather and handling rules affect a ball that is, on paper, almost identical from game to game.

A rounder ball in a different game

The first intercollegiate games, played in the late 1860s, looked much more like soccer than like modern football. The ball was closer to round, and players moved it mainly with their feet. As the sport drifted toward the rugby-influenced game that became American football, the ball changed with it. Rugby balls were oval, and the oval shape suited carrying and throwing better than it suited kicking along the ground. For a fuller picture of that early period, see The Origins of American Football: From Rugby and Soccer.

The word that many fans still use for the ball, "pigskin," also dates from this period, and it is misleading. Early balls did contain an inflated pig's bladder, which was placed inside a leather casing to hold the air. The leather outside was not pigskin, though; it was typically cowhide. The nickname is usually traced to the bladder, not the cover. Modern footballs use no animal bladder at all.

From animal bladders to rubber

An inflated animal bladder was an unreliable way to keep a ball round. Bladders varied in size and shape, they leaked, and they were not pleasant to inflate by mouth. During the nineteenth century, the development of vulcanized rubber made a better solution possible. A rubber bladder could be manufactured to a consistent shape and size, held air longer, and did not depend on the luck of the butcher.

That change, which arrived in the rugby and soccer world first and then in American football, standardized the inside of the ball. The leather casing around the rubber bladder remained, and in the early football era it was stitched and then laced shut, because the bladder had to be inserted through an opening that was closed afterward.

Why the ball got slimmer

The most important shape change came after the forward pass was legalized in 1906. Before that, the ball was carried or kicked, and a fat, rounder ball was fine for both. Once passing became part of the game, a ball that was easier to grip and throw offered an advantage. For the story of that rule change, see How the Forward Pass Became Legal.

Over the following decades, the rulebooks narrowed the permitted dimensions more than once, and the ball became slimmer around its middle. Historians tend to place the biggest slimming in the early part of the twentieth century, and the professional ball took something close to its modern shape by the middle of the century. If you are looking for the exact year of a given measurement change, a dedicated rules history will give you better detail than a summary can. The direction is not in question: as passing grew in importance, the ball became easier for a quarterback to hold and spin.

The shape that resulted has a geometric name, a prolate spheroid, which is a sphere stretched along one axis. In practice, it means a ball with two pointed ends and a circular cross-section in the middle.

What an NFL ball looks like today

The National Football League (NFL) rulebook specifies the ball in detail. Check the current rulebook for the exact language, but the published specifications are roughly these:

A few of these numbers are worth translating. A circumference of around 21 inches at the middle means a ball with a diameter of roughly 6 3/4 inches where it is fattest. The pressure range is well under half the pressure in a typical car tire, which is why a football feels firm but not rock-hard.

College and high school balls are similar in spirit but have their own published specifications, and the numbers are not identical to the NFL's. The rules at each level live in separate rulebooks written by the NCAA (the National Collegiate Athletic Association) and the National Federation of State High School Associations (NFHS), and some state associations adopt their own variations. If you need a precise measurement for a particular level or league, consult that rulebook.

How a football is made

A modern leather football is assembled from panels. A typical ball uses four panels of leather, which are stitched together inside out. The ball is then turned right side out through a small opening, a rubber bladder is placed inside, and the opening is laced shut. The ball is inflated, inspected and trimmed.

The leather itself is cowhide that has been tanned and then given a pebbled surface, a pattern of tiny bumps that improves grip. The pebbling is not decoration. It gives fingertips something to hold on to, especially when the ball is wet.

The NFL's official game ball has been made by Wilson for decades. The company's own history dates its relationship with the league to the early 1940s, and its pro football is nicknamed "The Duke," after Wellington "Duke" Mara, a longtime figure in the Giants organization. The company has made its footballs at a factory in Ada, Ohio, for a long time. Those details come from company and league history rather than from the rulebook, so treat the specific years as approximate.

Not every ball at every level is leather. Many high school and youth games use balls with composite covers, which are synthetic materials designed to hold up in wet weather and to cost less. Some players prefer leather, and some leagues require it, so the rules of your own league matter.

Why the laces are still there

The laces began as a necessity. When the bladder had to be inserted into the casing, the casing needed an opening, and laces were the way to close it. Later construction methods made the laces technically unnecessary for assembling the ball, but they stayed for a very practical reason: quarterbacks use them.

A passer places his fingers across the laces to get a grip and to control the spin of the throw. The laces give a fingertip something to push against at the moment of release, and the position of the fingers on them affects how the ball spirals. A thrown football that rotates around its long axis, a spiral, flies more steadily than one that tumbles end over end. A spinning object tends to keep its orientation as it travels, which reduces wobble and drag, so a well-thrown spiral loses less speed and goes farther.

Kickers, meanwhile, treat the laces differently. A holder on a field goal or extra point generally turns the laces toward the goal posts or away from the kicker's foot, because laces can disturb the contact. It is a small detail that you can watch for in any kicking attempt. To learn more about the evolution of kicking, see The History of Kicking: From Straight-On to Soccer-Style.

Air pressure, temperature and weather

Pressure matters because it changes how a ball feels and behaves. A ball inflated near the lower end of the legal range feels softer in the hands and may be easier to grip, while a ball near the upper end feels firmer and may carry a little differently. Within the legal range, quarterbacks and kickers often have preferences.

Weather affects the ball in ways that have nothing to do with the rulebook. The air pressure inside a ball falls as the air gets colder, because cold air takes up less space. A ball that is correctly inflated in a warm locker room can be a little softer when it sits in cold air on the sideline. Wet balls are slippery, and a muddy ball is harder to hold and kick. Teams practice with wet balls and sometimes use towels, gloves and other methods to keep their grip. For more about how conditions change what coaches call, see How Weather Changes a Game Plan.

Inflation drew national attention after a dispute over the pressure of balls in a playoff game in 2015, and the league tightened its procedures around ball handling afterward. The details of that case are beyond the scope of this article, but the lesson for any reader is that the rulebook treats ball pressure as a regulated matter, and officials check it.

Different balls for different players

A ball built for an adult professional is too large for a young child to throw or catch. Most youth and amateur leagues use smaller balls sized for the age group of the players. Names and sizes vary, but commonly seen categories include a very small size for the youngest players, a junior size, an intermediate or youth size, and a full-size version for older players.

If you coach or play in a youth or recreational program, ask the league which size and cover it uses. A ball that is too large for a player's hand makes throwing harder and encourages bad habits. You can find recreational options near you on the Play section, and you can find high school schedules and teams in the high school directory. College programs are listed on the college page.

Handling the ball in a game

In the NFL, game balls are not simply pulled out of a bag. Officials inspect the balls before the game, and each team prepares balls for its own offense. Other levels have their own procedures. A separate set of balls is used for kicking, and those balls are supposed to be new and unaltered so that no team can prepare them in a way that benefits its kicker.

Why would a team want to prepare its balls? Because a brand-new football can be slick and stiff, and players generally prefer one that has been broken in a little. Equipment staff may brush or rub balls to reduce the shine. The rulebook sets limits on what can be done to them, and the officials make the final decision on whether a ball is acceptable.

During play, a ball that goes out of play or is replaced because of damage is swapped for another one that meets the same specifications. You may notice a new ball arriving from the sideline after a long kick or a ball that lands in the stands. That is routine.

Common myths

1. "Footballs are made of pigskin." Not so. The cover is typically cowhide or a synthetic material. The name is usually traced to the animal bladder that used to be inside.
2. "The football has always been shaped like it is now." It began much rounder, and it became slimmer as passing grew in importance.
3. "The laces are only for show." They give passers a grip and help control the spin.
4. "Every football is the same." Size, material and pressure vary by level and league.
5. "Air pressure does not matter." Pressure affects feel and flight, and the rules regulate it for that reason.
6. "A football is a sphere." It is a prolate spheroid, which is why it bounces unpredictably.

The ball's unpredictable bounce is also part of what makes the sport so dramatic. When a fumble hits the ground, nobody, including the players, can say which way it will go.

The short version

• The first footballs were nearly round and contained an inflated animal bladder inside a leather cover; the "pigskin" nickname is usually traced to the bladder.
• Rubber bladders replaced animal ones, and the ball became slimmer after the forward pass was legalized in 1906.
• The NFL ball is 11 to 11 1/4 inches long, weighs 14 to 15 ounces, and is inflated to 12.5 to 13.5 pounds per square inch.
• Wilson has supplied the NFL's ball for decades, and the ball is assembled from leather panels, stitched inside out, turned and laced.
• Laces survive because they help passers grip the ball and control the spin of a spiral.
• Cold weather lowers the pressure in a ball, and wet or muddy conditions make it harder to hold.
• College, high school, youth and flag leagues each have their own ball specifications, so check your own league's rules.