DETROIT -- For proof positive that the irresistible force can, indeed, nudge aside the immovable object with some frequency, we present as Exhibits A and B the two starting fullbacks from the Super Bowl XL franchises.
In Mack Strong of the Seattle Seahawks and Pittsburgh Steelers counterpart Dan Kreider, the title game will feature two of the league's premier lead blockers. Two fullbacks who have combined to clear out holes for 1,000-yard rushers in 14 of their 19 aggregate years in the NFL. Two selfless veterans who live vicariously through running deeds of others; a couple of blue-collar players who might regard a train wreck as benign.
If you're one of those rubberneckers who slow their cars to a near halt to gawk every time you pass an accident on the road, well, get yourself one of the choice seats in front of the big-screen television for Sunday evening.
"People ask you what it's like," said Strong, a much admired 13-year veteran who finally grabbed a long overdue first Pro Bowl berth this season. "Well, think about running full-speed into a wall 50 or 60 times, headfirst, for a living. I mean, it's like banging a couple of locomotives together, really. People kid me that I'm three or four inches shorter now than when I came into the NFL, and they're probably right."
Strong, 34, is the other 13-year veteran running back in this week's game. And as he sees it, that's the natural and appropriate order, with Pittsburgh tailback Jerome Bettis inarguably the singular personality surpassing everything else that transpires here. But as Strong serves as the personal escort for record-breaking Seattle tailback Shaun Alexander, it is entirely conceivable The Mack Truck could play an even more significant role in Super Bowl XL than The Bus will.
Alexander joked Sunday night that Strong is like his gold credit card because he "[doesn't] go anywhere without him," and there is some truth to that statement. Over a long career for which he finally is garnering recognition, Strong has blocked for three 1,000-yard tailbacks -- Chris Warren, Ricky Watters and Alexander -- for a total of 11 thousand-yard seasons.
If he isn't really Alexander's gold card, Strong -- signed as an undrafted free agent in 1993 -- has become the gold standard of NFL lead blockers. Kreider, a sixth-year veteran who has followed a career path very similar to Strong's, is emerging as the same kind of player, an incredibly effective but largely anonymous player who earns his keep by bashing heads with linebackers all day.
"I'm betting between the two of them, they've probably broken a ton of face masks," Bettis said. "Their own and those of a bunch of defensive guys."
Ripping off their face masks actually might be about the only way Strong and Kreider could shed the anonymity. Between them, they have amassed only 453 "touches" -- rushing attempts or receptions -- in 19 league seasons, an average of 1.7 touches per game.
Strong has never reached the 40-carry or 30-reception mark in a single season. His best statistical year came in 2003, when he touched the ball 66 times from scrimmage, and his résumé includes only two runs of 20-plus yards. Kreider's numbers are even worse, with just 80 combined carries and receptions and never more than 24 touches in a season. He has just four touchdowns, 10 fewer than Strong's career total.
"It's just the way the [fullback] position has evolved," said Kreider, signed as a free agent from tiny New Hampshire in 2000 and released twice during his Steelers tenure. "It's not exactly a 'look at me' position, really, or one where you can be about personal gain. But that's OK. I mean, I respect the heck out of a guy like Mack Strong because he's never worried about himself. I think he's a good model for what the position is about."
Kreider, 28, is regarded by some league observers as a younger version of Strong. He is a squared-off (5 feet 11 and 255 pounds) blocker whose low-built frame provides him natural leverage, and, in a game in which the man who plays lower usually wins most of the battles, Kreider can be explosive at times. Steelers veterans recall the play during his 2000 rookie season in which Kreider jacked Baltimore middle linebacker Ray Lewis right off his feet with a lead block. The moment, replayed incessantly in the Pittsburgh film review that week, earned Kreider the nickname "Thunder."
"He's just one big muscle," Steelers nose tackle Chris Hoke assessed. "I mean, he's kind of the [personification] of the brick [outhouse], isn't he?"
There is nothing malodorous, though, about the performances of Strong and Kreider and what they could mean to their respective teams Sunday. Alexander and Mike Holmgren, the Seahawks' head coach, have gushed this week about Strong, about what he means to Seattle not only on the field but off it, as well. Holmgren termed Strong "just about my favorite player of all time."
Alexander, who scored many of his league-record 28 touchdowns in 2005 behind blocks on which Strong got a big enough piece of a defender to carve out a hole, eliminated all qualifiers from his praise.
"He makes it happen," Alexander said. "People talk about the guy at the bottom of the pile. Well, he creates the pileups, believe me. [If] you see us make a big run, look to see where he's at, and it's usually on top of a linebacker or something. You want to follow the ball? Then follow Mack, because he's usually the one leading the way."
Len Pasquarelli is a senior NFL writer for ESPN.com. To check out Len's chat archive, click here.