Few of us have one defining day in our life, one for which we forever will be remembered. Gale Sayers does: Dec. 12, 1965.

It was a wet, bone-chilling, see-your-breath day in Chicago. Sayers, a rookie halfback for the Bears, tied the NFL mark for most touchdowns in a game by scoring six against the San Francisco 49ers in a classic contest that has been featured many times in fuzzy, black-and-white TV highlights.

Despite the fuzz, fans remember it vividly. So does Sayers. It's difficult to forget a day spent sloshing knee-deep through the mud.

Sayers had a lot of magnificent days; enough to land him in the Pro Football Hall of Fame at age 34, the youngest inductee ever. Packing them into a short career makes them even more remarkable. In seven seasons (only 68 games because of two devastating knee injuries), Sayers collected honors more representative of a life's work.

"His days at the top of his game were numbered, but there was a magic about him that still sets him apart from the other great running backs in pro football," Pulitzer Prize-winning sportswriter Red Smith wrote. "He wasn't a bruiser like Jimmy Brown, but he could slice through the middle like a warm knife through butter, and when he took a pitchout and peeled around the corner, he was the most exciting thing in pro football."

The 6-foot, 200-pound Sayers was the 1965 Rookie of the Year after scoring 22 touchdowns, an NFL record that would stand 10 years and still is the rookie mark. He would only play three more full seasons, and in two of them, he would lead the NFL in rushing. Named to the Pro Bowl in each of his first five seasons, he was voted the outstanding back of those games three times.

A severe left knee injury in 1970 effectively ended his career. After playing only two games in 1971, he was finished at 28. In his career, he had gained 6,213 yards running and receiving and scored a total of 56 touchdowns, including eight on kickoff and punt returns. He averaged 5.0 yards a run on his 991 carries (for 4,956 yards). He had set seven NFL records and 23 team marks.

But numbers are simply inadequate to describe Sayers. Better to focus on his elusive moves. His hips gyrated like an exotic dancer's. Sportswriters called him "the football version of the three-card monte" -- now you see him, now you don't -- and "a movable feast."

Bears coach George Halas, who had seen many sensational backs (including the legendary Red Grange, who ran wild 40 years before Sayers), said, "Gale detects daylight. The average back, when he sees a hole, will try to bull his way through. But Gale, if the hole is even partly clogged, instinctively takes off in the right direction. And he does it so swiftly and surely that the defense is usually frozen."

Besides finding holes, Sayers was noted for his "cuts," changing direction and eluding tacklers without losing speed.

Even comedian Bill Cosby weighed in: "He is the man who splits himself in half and leaves the half without the football with the tackler."

Sayers was born on May 30, 1943 in Wichita, Kan. He grew up in Omaha, Neb., the son of a car polisher and mechanic. A star running back at Omaha Central High School, more than 75 colleges offered him scholarships. Sayers said he chose Kansas because he liked coach Jack Mitchell and it was close to home.

Sayers also ran track at Kansas, competing in the high hurdles, 100-yard-dash and even setting a school record for the long jump at 24-10 1/2. But it was on the gridiron that "The Kansas Comet" truly excelled, being a two-time All-American (1963 and 1964). He rushed for 2,675 yards in his Kansas career, including setting the NCAA record for the longest run from scrimmage, 99 yards against Nebraska in 1963.

Sayers was drafted by the Kansas City Chiefs in the AFL and the Bears in the NFL (fourth overall pick, immediately after Chicago selected another All-American, linebacker Dick Butkus). Despite a more lucrative offer from the Chiefs, Sayers chose the Bears, even though he described their counter-offer as "$4.95 and a carton of Cokes."

In his fifth game, Sayers scored four touchdowns in a 45-37 victory over the Minnesota Vikings. He did even better two months later in the Bears' 61-20 rout of the 49ers, with his six touchdowns equaling the record set by the Chicago Cardinals' Ernie Nevers in 1929 and tied by the Cleveland Browns' Dub Jones in 1951.

His scores came in a variety of ways: 80-yard screen pass, runs of 21, 7, 50 and 1 yards, and an 85-yard punt return. He accounted for 336 yards -- 113 rushing, 89 on receptions and 134 on punt returns.

For his rookie season Sayers accumulated 2,272 yards rushing, receiving and returning kickoffs and punts. In 1966, he ran for a career-high 1,231 yards in the 14-game season, winning the rushing title.

Two years later, though, his world fell apart. Midway through the 1968 season, in the midst of his best campaign to date, the 49ers' Kermit Alexander took out Sayers, who suffered a ruptured cartilage and two torn ligaments in his right knee. He was out for the season.

"The injury was only serious because they had to saw through muscles and nerves," said Sayers. "If they'd had arthroscopic techniques in those days, I'd have been back in a couple of weeks."

Despite the seriousness of the injury, Sayers began the slow process of rehab and physical therapy. He returned to the Bears' lineup in 1969 and ran for 1,032 yards, winning his second rushing title. He also was awarded the George Halas Award as "the most courageous player in professional football."

At the awards presentation, Sayers dedicated his prize to his friend and teammate, Brian Piccolo, who was dying of cancer. The story of his friendship with Piccolo was later immortalized in the 1971 made-for-TV movie "Brian's Song," which starred James Caan as Piccolo and Billy Dee Williams as Sayers. In his 1973 autobiography, "I am Third," Sayers also detailed his friendship with Piccolo.

In an exhibition game in 1970, Sayers suffered a stretched ligament in his left knee. He played two regular-season games with the injury, but couldn't maneuver with the same skill as he had previously and he was operated on. But the knee never felt right again. Despite all his rehab efforts, there would be no more quick cuts and no more successful comebacks.

"By 1971, he was playing out the string, his knees possessing all the consistency of Swiss cheese," one sportswriter observed.

In 1973, Sayers was hired as the assistant athletic director at Kansas. Soon after, he became director of the Williams Educational Fund, the fund-raising arm of the KU athletic department.

In 1976, he left Kansas to become the athletic director at Southern Illinois. Then in 1984, he formed Crest Computer Supply Co. in Chicago. The company became a success, posting sales of $55.2 million in 1994.

In a July 2000 chat with NFL.com, Sayers said, "We do hardware and service for Fortune 500 companies. So that's what I've been doing. We have nine locations around the country so I'm on the road about 15 days a month."

Sayers remained active in his community working for charities, including the Better Boys Foundation and the Brian Piccolo Cancer Research Fund.

Awards kept coming his way, too. He was elected into the College Football Hall of Fame, the Kansas Hall of Fame, and the Black Athlete's Hall of Fame. But no honor was more appreciated than his induction into the Pro Football Hall of Fame in 1977.

"I had a career that was very short, but it had a lot of thrills," Sayers said. "This tops them all."