You have to click back nine games in this series, to Dec. 26, 2004, to find a running back for the Steelers or the Ravens who gained 100 yards in a game against the Steelers or the Ravens, a challenge so improbable that it took a Hall of Famer at the apex of his thunderous powers to attain it.
That would be Jerome Bettis, who pounded his way to 117 yards on 27 missions that game, and no one's really approached the 100 plateau again as this Pittsburgh-Baltimore rivalry has grown to approximate the proportions of its legendary defenses.
Since 2000, in fact, the Steelers have allowed an average of 89 rush yards per game overall, a standard so foreboding to running backs that it is surpassed only by the 88.4 allowed by the Ravens for the same period. The Ravens haven't allowed a 100-yard rusher in the past 35 games.
Those violent, impactful, innovatively constructed defenses, particularly the 2008 editions, would indicate that Bettis' little monument will stand uneclipsed through Sunday's AFC championship game, but know this: Should Willie Parker or Le'Ron McClain find his way to 100, should even Mewelde Moore or Willis McGahee find it within himself, that man's team is headed for Tampa, Fla., and Super Bowl XLIII.
If not certainly, next to certainly.
At his first championship week news conference yesterday, Steelers coach Mike Tomlin came back to the relative virtues of both team's ground attacks again and again, reminding a clogged South Side media room of Baltimore's desire to "pound the big backs at you."
Though it's not a matchup problem for the Steelers in the strict sense of the term, there is a disparity here.
The Steelers have no big backs.
McClain is 260 pounds and McGahee is 232. Those weights appear to be published minimums. Parker is 209, which is no bigger than Moore, and those appear to be published maximums. Is it a problem that if you stood Parker and Moore behind McClain and McGahee, you wouldn't be able to see them?
Had the Steelers lost at Baltimore Dec. 14, a fate they avoided only by the grace of the replay booth, I would have pointed out that it just isn't possible to win the AFC North Division anymore without a back who is a lot more Bus-like, if not in heart and skill, then certainly by dimensions.
The issue lost its validity the moment Ben Roethlisberger's pass found Santonio Holmes' outstretched fingers and some intersection above the goal line in the Maryland darkness, but now it is recast as the question of which back can gain 100 Sunday, which is only another way of asking who will represent the AFC on Super Sunday.
"Willie Parker is mentally healthy," Tomlin said as the recoil to a question about his running back's apparent return to complete physical health. "When he feels good, there's a bounce in his step, and that rubs off on people. We feed off one another like that."
Doubtless the Ravens take similar inspiration from the exploits of McClain, who made his first Pro Bowl this year and dissuaded anyone who thought his talents did not include breakaway potential when he turned in the longest run from scrimmage by an opponent in the 37-year history of Texas Stadium, the 82-yard rumble that lifted Baltimore past the fading Cowboys Dec. 20.
McClain hurt his ankle in the car wreck of a football game Saturday at Tennessee but returned to play.
Most statistics, some relevant and some not, will tell you the Ravens are more capable in the run game than the Steelers, but for the extremely urgent meeting Sunday, the differences will be primarily in tactics. The Ravens will deploy something the Steelers almost never do -- an unbalanced offensive front that inserts an extra tackle to the formation's strong side.
"That's Cam Cameron football," Tomlin said, referring to the Ravens' offensive coordinator. "As opposed to blocking you with a 260-pound guy, or whatever [tight end Todd] Heap is [he's listed at 250], you put a 310-pound guy at the point of attack."
Though Tomlin said there are enough options in Baltimore's unbalanced set to "keep you honest," the danger is more than the fortified run.
"Our reactions to it are different," the head coach said. "It's important that we don't allow it to reduce what we're capable of, so sometimes we slide people [toward the overpopulated area] and sometimes we don't."
The best two defenses on earth, Pittsburgh's and Baltimore's, are not so much in the business of reaction as they are in the business of creating panic and breaking wills. The notion that the drama Sunday will preclude something so quaint as a 100-yard rusher remains fully intact. Still, it's worth aspiring to.
Gene Collier can be reached at firstname.lastname@example.org or 412-263-1283.