Evolution of the positions

How basic formations changed through NFL history

Many positions today bear little resemblance to the original positions and roles in the early days of football. They evolved over time as offenses and defenses changed to gain an edge over the other side.

The line

In the 20s, well before platooning was introduced, players played both sides of the football. The lines set up fairly identical to each other. There was a center flanked by two guards and two tackles. The tackles were bracketed by two ends. The 7-man offensive line set up close together. It had no player split outside like a wide receiver. There was no wide receiver or middle linebacker. The receiver was a flanker. He might be out to one side but he did not play on the line. He played a yard or two behind the line. The defensive line was also a 7-man line. Their positions were identical to the offensive line. In fact, the offensive center would play as the defensive center, the offensive guard would play as the defensive end, etc.

The ends and the linebackers

Offensive ends became the split end (lining up apart from the line) and tight end. Defensive ends evolved into cornerbacks who covered the split end and flanker. As such, the old defensive tackle became the new defensive end. The old defensive guard became the new defensive tackle.As offensive ends evolved into faster, pass-catching players, they were split out from the end of the line. They became split ends (more commonly called wide receivers today). The defense still had a line that matched the offensive line. This is the 5-2 defense where a lineman matches up with each offensive lineman. To counter the power running schemes of the 30s and 40s, the 5-2 was the most appropriate defense.

More linebackers

Quarterbacks began to exploit the 5-2 by finding the soft spots behind the defensive line. Defensive centers responded by sometimes dropping back into coverage. This position became the middle linebacker. This was the 4-3 defense. The 4-3 became the dominant defense during the 50s and 60s.

In the 70s, the 3-4 defense evolved to counter fast, powerful running backs. Three defensive lineman were tasked with occupying as many of the offensive linemen as possible to allow the four LBs to make the tackles. By the 90s, very few teams used the 3-4. It received a resurgence in the early 21st century.

The backs

The halfback and fullback positions are misnomers today. In the traditional I-formation or Pro Set, the positions have flipped. The halfback no longer lines up 'halfway.' He lines up at the end of the I (the most downfield position) while the fullback lines up in front of him in order to lead the block.

In the 90s and into the early 21st century, the fullback position shrunk in importance for most offensive sets. There are several factors.

• Offenses had more success adding an extra receiver.
• As defenses became better at filling holes, the fullbacks' role of blocking the pursuing LB did little other than plug up the hole. Offenses adapted by adopting zone blocking. Running backs adopted a 'run to daylight' (or 'run to the open gap') philosophy.
• Defenses used gap control to corral the running back. By keeping the TE instead of the FB, the line adds another gap to be defended. Spreading out the defense gives the running back more options.
• Some coaches prefer to carry an extra HB or TE on the roster instead of a FB.
• Players who in previous generations would be fullbacks have become TEs.