1900-1909

College football had been in existence even at this point for 31 years, but in the early days the game resembled something more like soccer. Not until Stanford's Walter Camp started tinkering with the rules in the late 1800's did the game we now know as football take shape. In 1900, prior rules changes had called for an eleven-man scrimmage system, and the "flying wedge" - invented by a Harvard chess expert - was outlawed. In 1906, St. Louis University became the first team to score on the newly legalized forward pass. Cornell University's Glenn S. "Pop" Warner invented the single wing in 1906. Most popular plays included Warner's "hidden ball trick," first used in 1903, and Amos Alonzo Stagg's "Statue of Liberty" play designed for his University of Chicago team in 1908. Most of the rule changes that gave rise to this new style of play came at the insistence of President Theodore Roosevelt who, in 1905, threatened to ban the game if the colleges could not find a way to end the brutality. Thus was born the NCAA (first known as the Intercollegiate Football Rules Committee).

Professional football was also beginning to take shape - first in Western Pennsylvania, then in the Massillon-Akron-Canton triangle of Northeastern Ohio. Unfortunately, gambling scandals hindered its growth.

During this decade, touchdowns were worth five points, a field goal was good for four. In 1909, field goals were reduced to three points and points after touchdown were introduced. In 1903, Harvard dedicated the nation's first modern football stadium. Fields were chalked with both vertical and horizontal lines, giving them a checkerboard or "gridiron" look.

1910-1919

In 1910, the new requirement of having seven men on the line of scrimmage brought an end to mass play and interlocking interference. The result was the first T-formation.

Coaches began to experiment with shifting personnel in an effort to draw on the momentum achieved in the "flying wedge" formation. The first shift was known as "tackles back," with the tackles lining up in the backfield but shifting forward at the snap. "Ends back," "guards back" and other shifts followed. The "Minnesota Shift" began with the center and two guards on the line of scrimmage and everyone else in the backfield. At the snap, the other eight players shifted until they were in proper position. The "Heisman Shift," introduced by Georgia Tech Coach John Heisman, started with only the center in his final position and everyone else shifting into a power formation at the snap of the ball. Heisman's Yellowjackets used this formation en route to a 222-0 drubbing of Cumberland College - the most lopsided game in the history of NCAA football - in 1916.

In 1917, coaching from the sideline, including sending in a substitute with a play, was prohibited.

College football teams began to form conferences in 1912 with what would eventually become the Big Ten. In 1914, the Southwest Conference was chartered, and in 1916 the forerunner to the Pac-10 was born.

Pro football received a shot in the arm in 1915 when the Canton Bulldogs signed former college and Olympic legend Jim Thorpe. Two former Notre Dame stars, Knute Rockne and Gus Dorais, played for the Massillon Tigers, and the Columbus Panhandles were led by the fabulous Nesser brothers - all six of them. But pro football was in a state of confusion - teams were loosely organized, players shifted allegiances weekly, and there was competition for the best players without controls of any kind.

1920-1929

In order to put an end to the state of confusion existing in the world of pro football, 11 representatives of teams met in an automobile showroom in Canton, Ohio, and formed what was to become known as the National Football League. Sadly, their brand of football would be considered boring by most. Nearly two-thirds of all NFL games from 1920 to 1932 were shutouts. The culprit for the lack of scoring was a fatter, harder ball being used by the league to actually discourage passing.

College football ruled the decade. These were the days of Notre Dame's Knute Rockne, George Gipp and the Four Horsemen; Red Grange, the "Galloping Ghost," from the University of Illinois; and "Wrong Way" Roy Riegels of the University of California. A crowd of 110,000 people watched the 1926 Army-Navy game at Chicago's Soldiers Field. The Big Six (later to become the Big Eight) was formed in 1928.

One of the most popular formations of the decade was the "Notre Dame Box," where a T-formation was shifted into a power formation on one side. Another prevalent offensive strategy of the day was Pop Warner's "double wing." But formations that used clever shifts eventually would become extinct when rule changes required that all players remain set for a full second prior to the snap of the ball.

1930-1939

The 1932 NFL Championship Game was significant, not only because it was the NFL's first championship game. But several rules changes that would greatly change all of football would be introduced after the game.

Due to extreme weather conditions, the game had to be moved indoors. Dirt and sawdust were brought in to cover the short (only 80 yards long) and narrow floor of Chicago Stadium. The new rules included the introduction of hash marks, moving the goal posts to the goal line, and from the controversial winning touchdown, henceforth all passes became legal from anywhere behind the line of scrimmage.

Before hash marks were part of the game, if a play ended near the sideline or out of bounds, the next play would start from the sidelines. With the hash marks, such plays would now being 10 yards from the sidelines.

Coaches could no longer get by on power, speed and trickery alone. They now had to learn how to play the hash marks with short and wide sides of the field in mind. George Halas and the Chicago Bears began spreading defenses with a T-formation that featured a man-in-motion. Eventually, the motion man became permanently stationed out wide and came to be known as a flanker. Also gone were the days of having eight or nine defenders on the line of scrimmage. The New York Giants won the 1934 NFL Championship with a 5-3 defense, which would become the standard defense for the next 10 years.

Another important development in 1934 came when the ball was reduced in circumference by one inch. This paved the way for TCU's Sammy Baugh to throw 11 touchdown passes, mostly out of spread formations designed by Coach Dutch Meyer.

Other highlights of this decade included the "Seven Blocks of Granite" from Fordham University and Coach Vince Lombardi; the formation of the Southeastern Conference in 1932; the first College All-Star game, showcasing the NFL champion vs. a team of college all-stars, at Soldiers Field in 1934; the University of Chicago's Jay Berwanger winning the first Heisman Trophy in 1934; and the birth of the Orange, Sugar and Cotton Bowls.

The decade's low point came in 1931 when Knute Rockne was killed in a plane crash.

1940-1949

A loss of manpower due to World War II prompted rule changes allowing free substitution with substitutes allowed to bring in plays from the sideline.

In 1947, University of Oklahoma Coach Bud Wilkinson began to develop college football's most dominant defense of the next 30 years - the 5-2, also known as the "Oklahoma" defense.

The pro's, however, were preferring a defensive set that featured five down linemen, two outside ends and a four-deep secondary - the "Eagle" defense, created by Coach Greazy Neale of Philadelphia.

Offensively, in 1949 VMI Coach Tom Nugent introduced the I-formation.

Four years prior to that, Purdue's Cecil Isbell became the first coach to direct his team from the press box. And George Connor, a tackle from Notre Dame, won the first Outland Award.

1950-1959

The 1950 Philadelphia Eagles were coming off successive NFL championships and Paul Brown's Cleveland Browns, just accepted into the NFL by way of merger, had won four straight All-American Football Conference Championships. Something had to give when the two teams met on opening day, and it was the "Eagle" defense.

Without a middle linebacker, the defense was woefully weak over the middle. And Otto Graham exploited the weakness, sending his two great ends, Dante Lavelli and Mac Speedie, across the middle, and running trap plays for Marion Motley.

In order to stop the Browns, New York Giants Coach Steve Owen devised the "umbrella defense," dropping the ends off to cover pass patterns. This use of the ends was the precursor to the modern day outside linebacker.

Later in the decade, as the split "T" and the passing game became more popular, teams began to drop their middle guard back into a middle linebacker position. This created the modern 4-3 defense.

The Detroit Lions won three NFL championships in the '50s, led defensively by "Chris' Crew," a secondary that featured Jack Christiansen and Yale Lary playing a rotating zone defense.

In college football, Missouri, Oklahoma and Maryland were devising innovative changes in offensive philosophy. Up to this point, offenses predominately tried to set up the defense with a series of moves aimed at trying to get the defense to react. But these schools developed new "T" systems in which the defense would make a commitment and the ball carrier would react away from it. Thus was born the belly series, with the quarterback sliding down the line, riding the ball into the belly of the back or keeping it, then handing off again, pitching it, or running with it. The triple option, wishbone and veer systems all evolved from the belly series made most popular by Oklahoma's Bud Wilkinson.

Free substitution was temporarily ended by the colleges in 1953, and the college game reverted to single platoon. Also in 1953, the Atlantic Coast Conference was founded.

In 1958, the colleges first gave teams the option of going for a two-point conversion after scoring a touchdown.

1960-1969

Two-platoon football returned to college football in 1964. Four years later, Darrell Royal of Texas perfected the wishbone offense - a staple of college football for the next 15 years. With this formation, Royal's Longhorns, Bear Bryant's Alabama Crimson Tide and Barry Switzer's Okahoma Sooners would record six national championships.

In the pro's, Green Bay Coach Vince Lombardi concluded that the NFL's 4-3 and zone defenses had become too complicated and it was time to return to the basics. The "Packers Sweep," with guards Fuzzy Thurston and Jerry Kramer pulling, and Paul Hornung and Jim Taylor carrying the ball, very much resembled plays out of the "single wing" and "Notre Dame Box" of the 1920's. When the defense stopped the sweep, Lombardi came back with the weak side slant - the same play made famous by the running of Jim Brown and still the most basic play in football today.

In 1960 and 1961, Coach Red Hicky of the San Francisco 49ers dusted off the old "single wing," called it the "shotgun," and ran it with much success until defenses learned it could be stopped through blitzing.

In celebration of college football's first 100 years, a panel of coaches, athletic directors and football writers named Knute Rockne the greatest coach up to that time.

1970-1979

The Miami Dolphins dusted off the "Oklahoma" defense, which was rejected by the pro's in the 1950's. Defensive coach Bill Arnsparger renamed it the "53" defense and enjoyed tremendous success with it as the Dolphins compiled a 17-0 record in 1972.

In 1974, Gary Davidson and a group of undercapitalized owners put together the World Football League (WFL). The league was short-lived, but several new rules introduced in the WFL caught the fancy of the fans - and of the NFL.

Among the changes brought by the new league: defensive backs were allowed only one bump on wide receivers, only two outside men from the kicking team were allowed downfield before the ball was kicked on punts, the penalty for offensive holding was reduced to 10 yards, goal posts were moved to the end lines, and teams kicked off from the 35-yard line instead of the 40. The results were predictable: more scoring.

By 1978, the NFL had limited the "bump zone" to a point within five yards from the line of scrimmage, and offensive lineman were now allowed to extend their arms when blocking.

The age of "Air Coryell," named for Chargers Coach Don Coryell, was dawning. A student of Sid Gillman's upfield or vertical passing attack, Coryell's offensive attack was emblematic of the exciting, high-scoring brand of football that had been played in the old American Football League.

Some colleges took note of the high-flying offensive schemes, and schools such as BYU began throwing the ball all over the place.

1980-1989

You can credit Bill Walsh of the San Francisco 49ers and Lavell Edwards of BYU with developing a better passing system that could win championships at any level. Their offensive style was a finesse attack with both ball control facets and big-play potential. This "West Coast" offense employed up to five receivers; incorporated a wide variety of formations, pre-snap motions and pass patterns; and utilized three-, five- and seven-step quarterback drops, along with "waggles" and bootlegs.

The 49ers won three Super Bowls in the '80s with this system, and BYU captured one national championship. A litany of Walsh's and Edwards' assistant coaches became hot properties. And college and professional teams from all over the country began adopting this new brand of modern football.

Despite the success of the new-fangled passing attacks, most college and NFL teams still remained ground oriented. Even when the wishbone, veer and other belly series formations began to disappear, the I-formation remained. To counter it, defenses went to a "press" defense - an attacking variation of Buddy Ryan's "46" defense made famous by the 1985 Chicago Bears Super Bowl team.

The New York Giants drafted Lawrence Taylor in the first round of the 1981 draft. Taylor became the prototypical outside linebacker - fast, quick, powerful and designed exclusively to get the quarterback. Thereafter, many college and NFL teams shifted to a 3-4 defense with Taylor's example in mind. To counter, Washington Redskins Coach Joe Gibbs began using a one-back offense that included an H-back - a second tight end to help create better running lanes by adding a blocker closer to the line.

Perhaps more so than in any decade, football coaching philosophy was a chess match of point-counterpoint during the 1980s.

1990-1999

By the early 1990s, offensive coaches such as Mouse Davis had begun to popularize multiple-receiver formations, where passes were thrown on nearly every play. This style eliminated slower tight ends and running backs almost entirely from the passing attack. The "run and shoot" offense was born. And it would enjoy some degree of success in the NFL, where it was utilized with varying degrees of success by the Houston Oilers, Detroit Lions and Atlanta Falcons.

In the "run and shoot," passing routes are determined by the coverage (man or zone). To its demise, the absence of a tight end in the offense caused problems, particularly in the red zone. By the end of the decade, this offense was a virtual dinosaur. However, the use of four and five wide receivers remained popular, particularly as an answer to the eight-man defensive fronts and press defenses that revolutionized the game in the mid-1990s. Even traditional running teams such as Alabama, Michigan and Oklahoma were using five wide receiver sets and empty backfields by 1999.

In case you haven't noticed, football is a fad sport. Each season, formations and strategy used by successful teams become the "hot, new way" to win.

Who knows what the next offense or defense du jour will be. Historically speaking, it will probably resemble something Stagg, Warner or Rockne did in the 1920s.