One time, after Willie Brown was well into retirement, I asked the man who invented the bump-and-run pass coverage technique to give me a demonstration of how it worked.

My ribs were sore for a week. He laughed about it for longer than that.

That was Willie Brown.

One of the greatest cornerbacks in NFL history, Willie passed away Tuesday after a long battle with failing health. He was 78, but if you ever saw him jack up some poor unlucky wide receiver and then run stride for stride with him down the field for 30 or 40 yards you only thought of him one way.

You thought of him blanketing receivers as if they had stickum’ attached to their jerseys. Or to his.

Lance Alworth, who Al Davis always believed was the game’s greatest receiver, was once asked by SI’s Paul Zimmerman, who always believed he was the game’s greatest football writer and might have been, what it was like trying to get free of the clutches of his old nemesis. Alworth described it this way.

“You’d escape Willie’s first bump and you thought you were free and – WHAM! – you’d get it again from somewhere you didn’t expect it,’’ recalled Alworth, who played against Brown 24 times during their careers in the AFL and NFL following the 1970 merger of the two leagues.

“It was always something to be concerned about, always something to get you off-balance. I could never take the inside on Willie. He’d square up on you, and you simply couldn’t get inside.’’

You couldn’t get much of anywhere on Willie Brown, who was the first great hands-on corner. At anywhere between 195 (his listed weight) and 215 pounds (often his real weight), the 6-foot-1 former Grambling linebacker had unusual size and strength for a cornerback. But he was blessed that it was coupled with a quick burst of speed that allowed him to be physical at the line of scrimmage and down the field while still able to run stride for stride with any receiver.

Those gifts, and Brown’s hard-nosed approach to football, made him a five-time AFL All-Star, a four-time NFL Pro Bowl selection, a two-time All-Pro, a member of the 1970s' NFL all-decade team and a first-ballot Hall of Famer in 1984.

Brown lasted 16 years in the NFL, all but the last as a starting corner, yet it almost didn’t happen. Undrafted, he signed with the Houston Oilers as a rookie free agent in 1963 and was asked to transition from college linebacker to professional corner. Before he had a chance to do it he was gone.

When asked how the Oilers could have missed on a guy who went on to sign with Denver and two years later intercept nine passes for the Broncos, Brown used to insist he was a victim of a quota system that limited the number of blacks on Houston’s roster. He claimed he thought he was one of the six African-Americans who would make the team that year …. only to be released at the end of the summer.

“I thought the quota was six,’’ Brown told me more than once. “Turns out it was five. I was number six.’’

Two years later Brown was an All-AFL corner for the first time and two years after that an intrigued Al Davis called Alworth, whom he became close to while serving as receiver coach of the Chargers before moving on to Oakland. Davis told him he had a chance to acquire Brown and wanted to know what he thought.

Alworth gave Brown the highest recommendation, but Davis was a master of the little details. So he asked if Brown was so good why had Alworth burned him badly in a game that season?

Alworth told Davis that Brown played hurt, limping with a bad ankle and a pulled hamstring. Thus informed, Davis made arguably the greatest trade of his long career, swapping a long forgotten defensive tackle named Rex Mirich and a third-round pick in 1967 for Brown and quarterback Mickey Slaughter.

Slaughter didn’t do much, but for the next 12 years Brown slaughtered opposing receivers and served as an anchor in the secondary for a team that would go on to play the Green Bay Packers in Super Bowl II that year.

Nine years and many iconic plays later, Brown, now 36, was back in Super Bowl XI with the first of the Raiders' three Super Bowl championship teams, and he made his presence felt all day.

The Raiders battered and pounded the Minnesota Vikings into submission, and Brown drove in the final nail when he intercepted a Fran Tarkenton pass in the flat in the fourth quarter and returned it 75 yards for a touchdown.

That play would be captured on NFL Films in the artful way that helped build the legend and the myth of the NFL. As Brown ran down the sideline the camera closed in on him until all that was on the screen was his face, his lips pursed as he blew air out and his eyes bulging wide and on fire as he ran.

Raiders’ legendary broadcaster Bill King’s call of that remains to this day a fixture of one of the Super Bowl’s greatest plays: “Old Man Willie! He’s going all the way!’’

Indeed he did, all the way to Canton and the Hall of Fame after completing his career with 54 interceptions, 39 coming with the Raiders. That remains the club’s career high, a record he shares with Lester Hayes. Add his seven post-season picks, and Brown finished with 61 … yet never thought intercepting the ball was really his job.

“My job wasn’t to catch passes,’’ Brown once said during a Hall-of-Fame interview. “My job was to stop the receiver from catching it. If I could have played 15 or 20 years without an interception that would have been fine. Anything beyond stopping a receiver, that’s gravy.’’

Part of that “gravy’’ came with some lumps, the kind Willie Brown delivered with such authority that it became a standard part of how corners were taught to play until 1978, when the effectiveness of that aggression was taken from the game with a rule allowing only one bump within the first five yards off the line.

Brown used to laugh and say, “Hell, I was just warming up five yards down the field. Then the real bumping started.’’

No one ever used that technique better than the man who invented it. To have changed the game is a rare thing in sports, but then Willie Brown was a rare athlete. But he was more than that. He was a charming, warm-hearted guy who knew not only how to play that technique but how to teach it.

Davis thought so highly of him that he installed him as secondary coach immediately after his retirement, and Brown remained in that spot for 10 years and through two Super Bowl victories before briefly becoming head coach at Long Beach State in 1991.

When the school gave up football, he continued working as a phys. ed. instructor, and in 1994 became head coach at Jordan High in Los Angeles for a year before returning to the Raiders’ front office. He remained there, a Raider to the end, until the day he died at the age of 78.

Willie Brown was a symbol of a time long gone in football. A time when people got hit from the snap of the ball to the whistle blow. And maybe even after it blew. He was one of the most physical corners in NFL history and one of its best.

But more than that, he was a Raider back when that meant something. I got the sore ribs to prove.