Don Pierson

Like other innovators at other times in NFL history, Bill Walsh adapted, created, copied, and invented. Because he succeeded so spectacularly, his legacy and influence puts him in the company of football icons George Halas, Paul Brown and Vince Lombardi.

Called a "genius" by sincere admirers and jealous rivals alike, Walsh took offensive football to new levels at just the time when NFL rules boosted and encouraged the passing game.

Though Walsh was kidded about wearing the genius label a little too comfortably, he also acknowledged that his "innovations" borrowed heavily from former "geniuses" such as Chicago Bears' assistant and Stanford coach Clark Shaughnessy and college and pro passing game wizard Sid Gillman.

The difference may have been in the timing. While Shaughnessy and Gillman were always ahead of their time in development of the passing game, Walsh came along at exactly the right time, his fertile mind perfectly juxtaposed with the league's desire to sell a more entertaining product than running and defense.

To Walsh, he came along too late, resentful that Brown passed him over as his successor with the Cincinnati Bengals after Walsh had spent eight years on Brown's staff.

Walsh wasn't hired by the San Francisco 49ers until age 47 in 1979 and quit only 10 years and three Super Bowls later — prematurely, he later lamented. Nevertheless, his impact could hardly have been more profound.

Bill Walsh, 1931-2007      Walsh dies after battle with leukemia  |     Opinion: Walsh’s genius found everywhere Fan reaction to Walsh’s death  |     Opinion: The father of modern NFL offenses Vote: Who is best NFL coach of all time? Opinion: Walsh belongs on Mount Rushmore

His "West Coast" offense is based on short, quick, timed passes by quarterbacks who read a progression of routes — first, second, third options. Receivers adjust routes to zone or man defenses and quarterbacks are able to throw to a spot, often before the receiver turns around, making it difficult for defenders to react. Versions of the system continue to spin off in different directions, all from the same roots.

Walsh was one of the first to use short passes as an extension of the running game. Other coaches criticized what they thought was a "soft" approach, forgetting that Walsh's teams also featured hard running and tough defense. He was also the first coach to "script" as many as 25 plays to start a game.

Oddly enough, Walsh traced his system to a forgotten little player named Virgil Carter, who became the Bengals' quarterback in 1970 with Walsh in charge of Paul Brown's passing game. Carter was replacing a prototype prospect named Greg Cook, whose promising career was  unfortunately ended by injury.

Don't miss this on MSNBC.com Pass it on: Sons of infertile men may be next The eight biggest Olympic marketing debacles Reality show judges range from wise to wacko Cosmic Log: Is this your jetpack? Forget your inhibitions: World's sexiest islands

"We had to devise a system to fit (Carter's) abilities," Walsh wrote in a 1990 book, "Building a Champion." "The timing of our passing game now became very important. Virgil would take three steps, throw, five steps, throw-short, quick throws within 10 yards of the line of scrimmage. That took advantage of Virgil's instincts and quickness, without forcing stress on his arm to throw passes deep down the field. Or, we would have him sprint out, to take advantage of his mobility, and again throw the ball short. We won our division with a 'nickel-and-dime' offense. Other people in the NFL couldn't believe Virgil could be that effective."

Later, Walsh was able to elevate his concept with Joe Montana, an eminently more gifted player than Carter, yet still not a can't-miss prototype. Montana was a third-round draft choice, yet whether it was Walsh's system or Montana's talent became an ongoing debate that often ignored the obvious conclusion that the two formed the kind of perfect union seldom realized in pro sports.