Years ago, Browns Hall of Famer Jim Brown was sitting in a small interview room in Berea, Ohio, trying to forearm shiver some sense into a young reporter too caught up in comparing great running backs.
"Why," said the man generally considered the greatest running back of all time, "would you want to take away from one great running style by trying to compare it to another great running style?"
Because, um, that's kind of what we nonrunners without great styles like to do between opening kickoffs.
"You can't make comparisons," Brown said. "A great running style is like a fingerprint or a voice on the phone that you know without having to look at the person's face. You should recognize it and enjoy the greatness without judging it against greatness that came before it or the greatness that will come later on."
Great running styles often can be summed up in one word. Brown was overpowering, like a man among children. Barry Sanders was nimble, like a ballerina in a bowling ball's body. Gale Sayers slashed and O.J. Simpson dashed. Earl Campbell was unbridled while Eric Dickerson was smooth.
The position faded as the NFL shifted to a passing league long ago. But something unusual has happened this season. At a point when all of us thought it was impossible for a running back to lead a rebuilding, one-dimensional throwback team to the brink of the playoffs, along came Adrian Peterson, a guy whose do-it-all style has proven difficult to sum up in one word.
"I'd say 'powerful,' " said quarterback Christian Ponder. "But it's a combination of power and agility. So I don't know."
"You want my one word?" asked right guard Brandon Fusco. "How about, 'Wow?' "
" 'Violent,' " said fullback Jerome Felton. "Definitely 'violent.' "
With 1,898 yards, Peterson stands one monster game from making this a season that would be remembered as the greatest by a running back in NFL history.
With a victory and 208 yards rushing in Sunday's game against the Packers at Mall of America Field, Peterson would break Dickerson's single-season rushing record of 2,105 yards, most likely clinch the league's MVP award and, oh yeah, lift the Vikings to a 10-6 record and the NFC's sixth playoff seed.
"I'd be satisfied with both," Peterson said with a smile. "I feel like I have a good chance. I believe it. And in order to accomplish it, you got to believe it."
Since tearing the anterior cruciate and medial collateral ligaments in his left knee on Christmas Eve a year ago, Peterson has proven the only thing that matters is what he believes is possible.
"There's a reason none of us believed him when he said he would come back better than ever, which he has," said Vikings personnel consultant Paul Wiggin. "The reason is no one could fathom that happening. To anyone. Ever."
Coach Leslie Frazier admits he wasn't sure what to expect.
"Adrian plants his feet and cuts harder than anyone I've ever seen," Frazier said. "Barry [Sanders] was a guy who was always cutting and darting, too. But not as violently. Barry was nimble. Adrian sticks that foot in the ground hard. It made me hold my breath until I saw him do it enough times."
Early in the rehabilitation process, Frazier approached Peterson about the possibility of having to change his running style. The conversation didn't last long.
Peterson said he doesn't remember Frazier bringing it up. Frazier remembers Peterson saying four words.
"He said, 'I don't think so,' " Frazier said. "And then what does he do? He comes back with the very same running style and he's  yards from 2,000."
Meanwhile, teammates are still searching for that one word.
" 'Explosive,' " said center John Sullivan. "But he's so well-rounded. He can play every style. I need more than one word."
Sorry. We're tight on space. Next.
"Is 'downhill' one word?" asked left guard Charlie Johnson. "If not, give me 'angry.' He runs like he's mad. Like he's going to beat someone up."
Rookie left tackle Matt Kalil said, "Nonstop," but then became distracted when told that Texans running back Arian Foster bought his offensive linemen Segways.
"Adrian will take care of us," Kalil said. "Especially if he gets that record. I might get a car."
Packers coach Mike McCarthy wasted no time picking a word to describe Peterson's style. It was fitting for the man who has rushed for 1,243 yards and eight touchdowns on 223 carries (5.6 yards per attempt) in 11 games against the Packers.
" 'Attacking,' " McCarthy said. "There's not enough recognition about his vision. His ability to see the second man. In my opinion, the great ones don't only worry about the first guy. The way he attacks the defense, he's extremely unique in that way."
Peterson is four weeks removed from blasting the Packers for 210 yards on just 21 carries. He is also running where he set the NFL single-game rushing record of 296 yards as a rookie.
But the Packers come into the game with a determination not to be embarrassed again. They also come in with Clay Matthews, who was injured and missed the first meeting.
"Clay Matthews is our best player on our defense and he's an impact player," McCarthy said. "Any time he's on the field, we're a better football team."
Meanwhile, Vikings right tackle Phil Loadholt gives up on the pursuit of a fancy one-word answer and says, "It's simple, but 'hard.' " Running backs coach James Saxon says, " 'Easy.' 'Fantastic.' " But former Vikings running back Chuck Foreman negotiates an extra word.
"I'll say, 'Aggressively aggressive,' " he said. "When a guy is that committed and works that hard, never bet against him. When the Lord made Adrian, he threw away that mold for sure."
A little Sweetness
Sorry, Jim, but the urge to compare is sometimes too great.
Frazier compares Peterson to Walter Payton, whom he played with in Chicago.
" 'Competitor' is the word I'd use for Walter," Frazier said. "A guy trying to tackle him, Walter wanted to run over him. A guy trying to outrun Walter? He wanted to outrun him. He always in his mind that, 'I'm going to be the best.' "
" 'Focused' is how I'd describe Adrian," Frazier said. "Or, actually, 'determined' might be the better word. Very determined. He's a lot like Walter."
Wiggin played for the Browns throughout Brown's entire nine-year career (1957-65) in Cleveland.
"The word I'd use for Jim is 'war,' " Wiggin said. "One of the greatest runs Jim Brown ever had went for 2 yards. He beat back about five guys and took it into the end zone for a touchdown."
"I'd say, 'obsessed,' " Wiggin said. "He and Jim are so much alike. So many times, Adrian will do something and I'll say to myself, 'Jim Brown.'
"If you remember that run in Cleveland [in 2009], when Adrian used his forearm to club that defender [cornerback Eric Wright] out of bounds. That was so Jim Brown."
OK, Jim. We're done comparing. We have only one person left to weigh in.
One word, Adrian. Go.
" 'Vicious,' " he said to a scrum of reporters who then set the North American land speed record for tweeting a player's answer to a question. "I guess you can say that."
Yes, Adrian, you definitely can say that.