Former San Francisco 49ers head coach Bill Walsh poses with a bust of himself after being inducted into the Pro Football Hall of Fame in 1993. Walsh, the ground-breaking football coach who won three Super Bowl titles and perfected the ingenious schemes that became known as the West Coast offense during a Hall of Fame career with the San Francisco 49ers, died today. AP file photo | July 1993

Walsh died early today following a long battle with leukemia, according to Stanford University.

Walsh didn't become an NFL head coach until 47, and he spent just 10 seasons on the San Francisco sideline. But he left an indelible mark on the United States' most popular sport, building the once-woebegone 49ers into the most successful team of the 1980s with his innovative offensive strategies and teaching techniques.

The soft-spoken native Californian also produced a legion of coaching disciples that's still growing today. Many of his former assistants went on to lead their own teams, handing down Walsh's methods and schemes to dozens more coaches in a tree with innumerable branches.

Walsh went 102-63-1 with the 49ers, winning 10 of his 14 postseason games along with six division titles. He was named the NFL's coach of the year in 1981 and 1984.

And few men did more to shape the look of football into the 21st century. His cerebral nature and often-brilliant stratagems earned him the nickname "The Genius" well before his election to the Pro Football Hall of Fame in 1993.

Walsh twice served as the 49ers' general manager, and George Seifert led San Francisco to two more Super Bowl titles after Walsh left the sideline. Walsh also coached Stanford during two terms over five seasons.

Even a short list of Walsh's adherents is stunning. Seifert, Mike Holmgren, Dennis Green, Sam Wyche, Ray Rhodes and Bruce Coslet all became NFL head coaches after serving on Walsh's San Francisco staffs, and Tony Dungy played for him. Most of his former assistants passed on Walsh's structures and strategies to a new generation of coaches, including Mike Shanahan, Jon Gruden, Brian Billick, Andy Reid, Pete Carroll, Gary Kubiak, Steve Mariucci and Jeff Fisher.

Walsh created the Minority Coaching Fellowship program in 1987, helping minority coaches to get a foothold in a previously lily-white profession. Marvin Lewis and Tyrone Willingham are among the coaches who went through the program, later adopted as a league-wide initiative.

He also helped to establish the World League of American Football — now NFL Europe — in 1994, taking the sport around the globe as a development ground for the NFL.

Walsh was diagnosed with leukemia in 2004, and underwent months of treatment and blood transfusions. He publicly disclosed his illness in November 2006, but appeared at a tribute for retired receiver Jerry Rice two weeks later.

While Walsh recuperated from a round of chemotherapy in late 2006, he received visits from former players and assistant coaches, as well as California Gov. Arnold Schwarzenegger and Sen. Dianne Feinstein.

Born William Ernest Walsh on Nov. 30, 1931 in Los Angeles, he was a self-described "average" end and a sometime boxer at San Jose State in 1952-53.

Walsh, whose family moved to the Bay Area when he was a teenager, married his college sweetheart, Geri Nardini, in 1954 and started his coaching career at Washington High School in Fremont, leading the football and swim teams.

He had stints as an assistant at California and Stanford before beginning his pro coaching career as an assistant with the AFL's Oakland Raiders in 1966, forging a friendship with Al Davis that endured through decades of rivalry. Walsh joined the Cincinnati Bengals in 1968 to work for legendary coach Paul Brown, who gradually gave complete control of the Bengals' offense to his assistant.

Walsh built a scheme based on the teachings of Davis, Brown and Sid Gillman — and Walsh's own innovations, which included everything from short dropbacks and novel receiving routes to constant repetition of every play in practice.

Though it originated in Cincinnati, it became known many years later as the West Coast offense — a name Walsh never liked or repeated, but which eventually grew to encompass his offensive philosophy and the many tweaks added by Holmgren, Shanahan and other coaches.

Much of the NFL eventually ran a version of the West Coast in the 1990s, with its fundamental belief that the passing game can set up an effective running attack, rather than the opposite conventional wisdom.

Walsh also is widely credited with inventing or popularizing many of the modern basics of coaching, from the laminated sheets of plays held by coaches on almost every sideline, to the practice of scripting the first 15 offensive plays of a game.

After a bitter falling-out with Brown in 1976, Walsh left for stints with the San Diego Chargers and Stanford before the 49ers chose him to rebuild the franchise in 1979.

The long-suffering 49ers went 2-14 before Walsh's arrival. They repeated the record in his first season, with a dismal front-office structure and weak-willed ownership. Walsh doubted his abilities to turn around such a miserable situation — but earlier in 1979, the 49ers drafted quarterback Joe Montana from Notre Dame.

Walsh turned over the starting job to Montana in 1980, when the 49ers improved to 6-10 — and improbably, San Francisco won its first championship in 1981, just two years after winning two games.

Championships followed in the postseasons of 1984 and 1988 as Walsh built a consistent winner and became an icon with his inventive offense and thinking-man's approach to the game. He also showed considerable acumen in personnel, adding Ronnie Lott, Charles Haley, Roger Craig and Rice to his rosters after he was named the 49ers' general manager in 1982 and the president in 1985.

"Bill pushed us all to be perfect," Montana said years later. "That's all he could handle as a coach, and he taught all of us to be the same way."

Walsh left the 49ers with a profound case of burnout after his third Super Bowl victory in January 1989, though he later regretted not coaching longer.

He spent three years as a broadcaster with NBC before returning to Stanford for three seasons. He then took charge of the 49ers' front office in 1999, helping to rebuild the roster over three seasons.

But Walsh gradually cut ties with the 49ers after his hand-picked successor as GM, Terry Donahue, took over in 2001. Walsh was widely thought to be disappointed with John York, DeBartolo's brother-in-law who seized control of the team in 1998 and presided over the 49ers' regression to the bottom of the league.

But Walsh stayed active with charity work, writing, lecturing and posts on various advisory boards. He also became more involved at San Jose State, directing a search committee to hire a new athletic director and football coach in 2004, and served in various leadership positions at Stanford.

Walsh wrote two books and taught classes at the Stanford Graduate School of Business.

"I'm doing what I want to do," he told the AP in an interview in 2004. "I hope I never run out of things that interest me, and so far, that hasn't happened."