The Mitchell Report attempted to explain the suspicious performances of a generation of baseball players. The NFL would probably like to avoid an investigation into the evolution of their seemingly superhuman players.

The modern athlete is an improbable combination of size, speed and strength, yet one of the best players on the field tonight at the Metrodome will be a guy whose abs look more like a pony keg than a six-pack.

Pat Williams, the Vikings' dominant nose tackle, doesn't look particularly powerful. He's not fast. He's shaped more like a lowercase m than a capital V. And he might be the most valuable player on a team that has won four in a row and could enter the playoffs on a seven-game winning streak.

Adrian Peterson is the Vikings' most spectacular player, but while this team has won and the running game has thrived even with Peterson injured, Williams remains the primary reason for what has been the best run defense in the game the past two seasons.

His workout secret? "I don't do nothin' special," Williams said. "It's all about the hands."

Most great nose tackles have three common traits: low centers of gravity; an obstinance that allows them to think of constant double-teams as little more than inconveniences; and powerful hands.

"Every day I walk around the house, squeezing those gripper things," Williams said. "That's what people don't understand. They want you to do all the speed and agility stuff. If you can't take it to the field, it's worthless. I've seen a lot of guys who lift lots of weight and look good on the scales, and they get to the NFL and they don't do nothin'. I've seen a lot of first-round busts."

Buffalo signed Williams in 1997 as an undrafted free agent out of Texas A&M. He signed with the Vikings the year before Brad Childress arrived.

"He's the heart and soul of our team, and it's interesting, when I had my first press conference, I didn't know Pat Williams except for his name and having competed against him," Childress said. "I walk in that door and look up at him, and he said, 'Don't worry coach -- I got your back.' I was like, 'Who is this guy?' " 

Now he knows. Childress said Williams makes a sport out of complaining.

"It doesn't make any difference whether it's what time we eat or what time we practice or what uniform we're wearing. If [complaining] was a sport, he'd excel at it," Childress said. "You'd want him on your team.

"He's a great guy to be around, and he's got thick skin, because he gets it dished at him as hard as he dishes it out. He doesn't let people hang around the training room, although he's a fixture there. If you open that door and come in there you better be ready for both barrels, whether you're a rookie or a veteran."

Williams has been known to talk on the field, too, although his verbal feud with Bears center Olin Kreutz is over. Williams has turned his attention to rookies, and the Other Williams, fellow defensive tackle Kevin.

"I talk to the young guys," Williams said. "I respect veterans, guys like Larry Allen. And Kreutz -- we've got a good relationship now. Not early.

"Kevin and me, we talk 24-7, every night, every day. We're like brothers. Sundays, we'll talk smack to each other, we're always trying to outplay each other. That's why we play so good every week."

Williams takes game film home with him, spending an hour every night in his basement looking for the subtle movements that give away the tendencies of centers and guards. He moved to Minnesota so he could spend the offseason "doing whatever the team wants."

Tonight, Williams will have the whole nation watching him. More precisely, watching Bears backs disappear beneath his bulk.

Asked which offensive linemen give him the biggest challenge, Williams scoffed, as if tossing away an underweight center.

"Ain't really nobody gives me trouble," he said. "Sunday morning, Sunday afternoon, Sunday night, Monday night, I'm going to make plays, no matter what. I love what I do."

Jim Souhan can be heard Sundays from 10 a.m.-noon on AM-1500 KSTP. • jsouhan@startribune.com