How Offensive Systems Spread: The History of Coaching Trees

By 4Football Staff · October 28, 2026 · 10 min read

Football ideas travel through people. This is how coaching trees work, which famous ones shaped offense and defense, and why a coach's ideas do not always survive the trip.

When a team installs a new offense, the playbook rarely comes from nowhere. A coordinator learned it from a head coach who learned it from someone else, who borrowed it from a clinic talk or a rival's film. Follow that chain of hiring and mentoring backward and you arrive at the idea of a coaching tree: a map of who worked for whom, and what they took with them when they left.

Coaching trees are one of the most popular ways to talk about football history, and also one of the most misunderstood. They are useful because the sport really does spread by apprenticeship. They are misleading when people treat them as proof that one man's genius caused every success downstream. This article explains how trees work, walks through several of the best-documented ones, and looks at what a tree can and cannot tell you. It is a history, not a scouting report, so it avoids current staffs; for who is coaching today, the teams pages are the place to look.

What a Coaching Tree Is

A coaching tree starts with a head coach, the trunk, and follows the assistants who worked for him and later became head coaches themselves, the branches. Their own assistants who become head coaches are the next branches, and so on. The idea is intuitive, but a few details are worth knowing.

• There is no official list. Trees are drawn by writers and fans, and different people draw different trees. One person counts only direct assistants, another includes players who became coaches, a third includes anyone who spent a year on the staff.
• People belong to more than one tree. A coordinator might spend years under one head coach, then years under another. He carries pieces of both.
• Trees describe hiring, not agreement. A coach can work for a man and then reject most of his ideas.

With those cautions in mind, the pattern is real. Football staffs are small, the work is secret and specialized, and head coaches tend to hire people they know, trust, or have seen succeed. Ideas follow those relationships.

Why Systems Travel With People

There are several reasons why an offense or defense spreads through a staff rather than through a book.

1. The playbook is not the system. A playbook shows plays. It does not show why a coach chooses a play on third-and-four, how he teaches the footwork, or what he does when it fails. That knowledge lives in people, and the only way to get it is to work alongside them.
2. Vocabulary is a language. Many offenses use a coded vocabulary in which a short phrase describes the formation, the blocking and the routes. A coach who learned the language can run a new team in the same words. A staff that shares a vocabulary can make adjustments in seconds. For more on how plays are written down and communicated, see the history of the playbook.
3. Careers run on trust. An assistant who has seen a head coach handle a bad loss, a difficult player or a long season knows what working for him is like. A head coach who has seen an assistant do the job knows what to expect.
4. Staffs are the ladder. To become a head coach, you generally have to be a coordinator. To become a coordinator, you generally have to be a position coach. The people who give you each job tend to be the people you already worked for. College coaching staffs describes the roles on that ladder.

An Early Example: A Lucky Staff in New York

One of the best-known examples of a staff that shaped the sport happened almost by accident. In the 1950s, the New York Giants had a head coach, Jim Lee Howell, who led the team with two assistants who would become two of the most famous coaches in the history of the league: Vince Lombardi ran the offense, and Tom Landry ran the defense. Lombardi had previously served on the staff at Army, under Earl "Red" Blaik, a coach whose own staffs produced several notable names.

Lombardi left for Green Bay in 1959 and Landry left for Dallas in 1960. Each built a long-running team, and each trained assistants who became head coaches. Landry's staff in Dallas included men who went on to lead teams of their own; Mike Ditka, Dan Reeves and Gene Stallings are among those who spent time on his staff. What the story shows is that a tree can begin with a staff meeting that nobody planned. Howell is rarely listed as a genius, but his decision to let two ambitious coaches run their units created a lasting influence on the sport.

Paul Brown and the Professional Coach

Paul Brown is one of the great trunks of the football tree because he did more than invent plays. He shaped how a coaching staff works. Brown won championships in the All-America Football Conference and the NFL with Cleveland, and later founded the Cincinnati Bengals. Over his career he used full-time assistants, systematic film study, written tests for players and organized practices, practices that are standard now and that were novel in his time.

Brown's staff in Cincinnati included Bill Walsh, who worked as an assistant there before taking head-coaching jobs in college and then with the San Francisco 49ers. Walsh would become the trunk of one of the most famous trees in football.

Bill Walsh and the West Coast Offense

Bill Walsh's offense is built on short, timed passes, precise footwork, scripted opening plays and a flexible approach to personnel. It is often called the West Coast offense, a label Walsh did not choose. The details of the system are covered in the West Coast offense explained; this section is about how it spread.

Walsh's assistants at San Francisco included several who became head coaches: George Seifert, who succeeded him in the head job, Mike Holmgren, who coached the team's quarterbacks, Dennis Green and Ray Rhodes. Holmgren became head coach in Green Bay and later in Seattle, and Andy Reid served on his Green Bay staff before becoming head coach in Philadelphia and later in Kansas City. John Harbaugh, who later became a head coach in Baltimore, spent years on Reid's staff in Philadelphia as a special teams coach and then a defensive backs coach.

That is a long chain, five or six links from Walsh to coaches working long after his death. It is not an exact genealogy, because each coach modified what he inherited. By the time the system reached a given team, it might differ in important ways. Still, the shared vocabulary and the shared emphasis on the passing game's timing and on a quarterback's decision making are traceable along these lines.

A New England branch

Another well-documented lineage comes through the New England Patriots, whose offensive terminology has been traced back to a system associated with Ron Erhardt and Ray Perkins, two coaches who worked together in the 1970s and 1980s. That system, which names plays by concept rather than by a long list of memorized calls, was later carried forward by coaches who worked in New England. It is a good example of how a way of naming plays can outlast the people who invented it.

Parcells, Belichick and the Defensive Side

Trees do not belong only to offenses. Bill Parcells coached the New York Giants and several other teams, and his staffs produced a number of notable coaches. Bill Belichick was a defensive assistant and later defensive coordinator for Parcells in New York. Tom Coughlin worked on Parcells's Giants staff and later became a head coach himself. Sean Payton was an assistant for Parcells in Dallas before becoming a head coach in New Orleans.

Belichick's own branch includes Nick Saban, who served as defensive coordinator for him in Cleveland before moving to the college game and building a long career, and Romeo Crennel, who was his defensive coordinator in New England. Saban's own staffs later produced head coaches in the college ranks. Here again the chain is real, and it crosses levels: a defensive philosophy moved from the pros to college through a single assistant.

Pittsburgh and the Dungy Branch

Chuck Noll led the Pittsburgh Steelers for more than two decades and, in a league full of famous trees, is better known for his teams than for his assistants. But one assistant became a trunk of his own. Tony Dungy worked on Noll's staff in Pittsburgh before becoming a defensive coordinator elsewhere and then a head coach in Tampa Bay and Indianapolis. Lovie Smith and Mike Tomlin both worked on his staff in Tampa Bay and later led teams of their own. The Dungy branch is associated with a defensive approach built on speed, simplicity and fast execution, but as with every tree, the coaches who left his staff did not all run the same system.

College Football's Trees

College football has its own trees, and they are as old as the professional ones. Woody Hayes at Ohio State and Bo Schembechler at Michigan are a classic pair, because Schembechler worked on Hayes's staff before taking the Michigan job, and the two later became rivals in one of the sport's most famous series. Hayes's staff also included Earle Bruce, who went on to become a head coach himself. Paul "Bear" Bryant at Alabama had former players and assistants who went on to lead programs of their own, including Gene Stallings.

In the modern era, the Air Raid offense spread through a chain of coaches who worked for or played for its creators and then took jobs elsewhere. Its history is covered in the Air Raid offense: origins and core concepts. The pattern is the same as in the pros, with one difference: college staffs turn over faster, so the branches spread more quickly.

Ideas That Move Without a Hire

Not every idea travels through a staff. Football also has a long tradition of borrowing in the open, and the borrowing is part of why trees are an incomplete picture.

• Clinics. For much of the twentieth century, coaches gathered at winter clinics where successful coaches presented drills, schemes and philosophy. High school and small-college coaches carried those ideas home, and a system could spread widely without any of the speakers ever hiring an assistant.
• Film. Coaches study their opponents on film, and what they see on film they sometimes copy. Sid Gillman, a coach often credited with pushing the sport toward a deeper passing game, was known for his early emphasis on film study, and his methods were widely imitated.
• Copying what works. When a team wins with a new formation or a new concept, other teams try it the next season. The league is a copycat league, and the speed of copying has only increased as film and data have become easier to share.
• Books and now video. Playbooks, instructional books and online video let young coaches learn systems they have never seen in person.

The practical result is that a given offense is rarely the pure product of one tree. It is a blend: some of what the coordinator learned from a mentor, some of what he borrowed from a rival, and some of what he changed to suit his quarterback.

A Summary Table

This table is a starting point, not a complete record. Other writers will list more names and a few may place people differently.

What a Coaching Tree Cannot Tell You

Treat any tree with some skepticism. There are good reasons.

• Success is not inherited. Many assistants who left famous staffs failed as head coaches. A tree shows who was hired, not who won.
• Selection bias. Trees get drawn after the fact, around the successful coaches. The assistants who did not become head coaches are usually left out.
• Luck and timing. Whether an assistant gets a head job depends on openings, owners and results that have little to do with ideas.
• Adaptation. A system that worked with one set of players may not work with another. The best branches change the system to fit the roster.

The honest summary is that ideas spread through people, and the people matter, but the roster, the opponent and the moment matter as well.

Following the Ideas as a Fan

You can use this history as a lens when you watch a game. Notice the vocabulary a broadcaster uses for a play, look at who a team's coordinator worked for before, and compare how two offenses with a shared ancestor line up. The schedule and college pages show you where to watch, and the players pages show how individual players fit into a system.

The Short Version

• A coaching tree maps who worked for whom; it is drawn informally, and different writers draw it differently.
• Systems spread through people because playbooks do not capture the teaching, the vocabulary or the judgment.
• Famous staffs sometimes form by accident, as with Howell's two Giants coordinators, Lombardi and Landry.
• The Brown, Walsh, Holmgren and Reid line is one of the best-documented offensive lineages; the Parcells and Belichick line is a leading defensive one.
• College football has its own trees, and the Air Raid offense is a modern example of an idea spreading through former players and assistants.
• A tree shows hiring, not agreement or success; many branches fail, and many succeed by changing the system they inherited.