ESPN celebrates the 100th anniversary of Vince Lombardi's birth with the "Greatest Coaches in NFL History" series, saluting the finest innovators, motivators, tacticians, teachers and champions ever to stalk the sidelines. Follow along as we reveal our list of the top 20 coaches of all time and document the lineage of the league's most influential coaching trees.

Marv Levy coached the Buffalo Bills to four consecutive Super Bowls in the 1990s, an unprecedented feat, but his teams never won the big game.

After graduating from high school in Chicago, Levy enlisted in the military and served until the end of World War II. Later, before one of the Bills' Super Bowl appearances, Levy famously said, "This is not a must-win; World War II was a must-win." After the war, Levy earned a bachelor's degree in English literature from Coe College in Iowa, and a master's in English history from Harvard.

Levy started coaching at the high school and collegiate level, including as head coach at New Mexico, California and William and Mary. At Cal, Levy gave a high school coach named Bill Walsh his first college job. The entire Cal staff was fired after three seasons, but Levy and Walsh wound up doing all right for themselves.

Levy's first NFL job came in 1969 with the Philadelphia Eagles. In 1970, he joined George Allen's staff with the Los Angeles Rams as special teams coach, and he followed Allen to the Washington Redskins the next season.

In 1973, Levy became coach of the CFL's Montreal Alouettes, leading them to three Grey Cup appearances and two championships in five seasons. Levy returned to the NFL as head coach in Kansas City in 1978. The Chiefs never reached the playoffs under Levy, but they improved in each of his first four seasons. They peaked at 9-7 in 1981 before falling to 3-6 in the strike-shortened 1982 season, after which Levy was fired.

Levy took a break from coaching, then worked for a season in the USFL. The Bills, who'd staggered to consecutive 2-14 marks in 1984 and '85, hired Levy as head coach midway through the 1986 season. That happened to be the first NFL season for another ex-USFLer -- future Pro Football Hall of Famer Jim Kelly. Kelly turned out to be the perfect quarterback to run Levy's no-huddle offense, which kept defenses on their heels and unable to make adjustments.

In 1988, the Bills reached the AFC Championship Game in what would be the first of six consecutive playoff trips, a streak that was capped by four straight Super Bowl appearances. The most heartbreaking of Levy's four championship losses was the first, when Bills kicker Scott Norwood missed wide right on a 47-yard field goal attempt with seconds remaining in what would be the New York Giants' 20-19 Super Bowl XXV victory. The other three losses were each by at least 13 points.

Levy retired after the 1997 season (one year after Kelly's career ended), having taken the Bills to the playoffs eight times in his 11 full seasons. At the time, Levy was 10th on the list of career coaching victories. He was inducted into the Pro Football Hall of Fame in 2001, and later returned to the Bills in a front-office capacity.

-- Kevin Stone

LEVY THROUGH THE EYES OF A PLAYER: JIM KELLY

I think Marv Levy's biggest achievement is keeping his team mentally focused year after year after year, especially during that run of four Super Bowls. We went five years to the AFC Championship Game. Everybody knows you've got to be physically prepared for the game. If you're not, you're not going to make it. But to be able to mentally prepare your football team after a devastating loss, and forget about what happened the year before or the year before or the year before, and the resiliency our football team had, it started with Marv Levy. I know we wouldn't have gone to four Super Bowls in a row without Marv Levy.

Probably the most influential thing about him was the way he handled the players on his team. If you remember, the guys we had -- Bruce Smith, Thurman Thomas, Andre Reed, Darryl Talley, Steve Tasker -- we had a bunch of different personalities, and we all had egos. Early on in Marv's career and our careers, we knew if we didn't come together as a team, it didn't matter how many superstars we had, we wouldn't make it. He made sure to make each individual understand that if we didn't put our egos to the side, we wouldn't achieve our goals. He could communicate to players in a way where we totally understood it. He was never the rah-rah, in-your-face type of guy. It was the old cliché: It's not what you said, but how you said it. Marv always knew what to say and how to say it.

It clicked probably in 1988. The Bickering Bills came and I had something to do with that. Everybody did to a certain point. We went to the AFC Championship Game in 1988. We knew our football team was talented. In 1989, our egos started getting in the way, including myself. Marv knew what we could achieve, but we couldn't if we started pointing fingers at each other.

To go back to back to back to back, that will never happen again. Nope. Period. The further we're removed from those games, the more people appreciate what we did. And it started with our head coach, Marv Levy.

-- Former Bills quarterback and Hall of Famer Jim Kelly, as told to Ashley Fox

ESPN "Greatest Coaches in NFL History" voting panel: Chris Berman, Jeffri Chadiha, John Clayton, Colin Cowherd, Mike Ditka, Gregg Easterbrook, Herm Edwards, David Fleming, Ashley Fox, Greg Garber, Mike Golic, Suzy Kolber, Eric Mangini, Chris Mortensen, Sal Paolantonio, Bill Polian, Rick Reilly, Mike Sando, Adam Schefter, Ed Werder, Seth Wickersham, Trey Wingo.