Five nuggets of knowledge about Week 15:
Forget about running the ball: The San Francisco 49ers own the NFL's longest ongoing streak of games without allowing an individual 100-yard rusher. The streak dates to Ryan Grant's 129-yard game for Green Bay in Week 11 of the 2009 season. The 49ers' Week 15 opponent, Pittsburgh, hasn't allowed very many, either. Baltimore's Ray Rice (twice) and Houston's Arian Foster are the only players to rush for 100-plus yards against the Steelers since the 49ers' streak began. We should not expect much from Frank Gore and Rashard Mendenhall on Monday night, in other words.
Keep an eye on that fourth quarter: The 49ers are allowing only 14 points per game. That would be the second-lowest average allowed in franchise history if sustained over the season. Opponents have scored 42.3 percent of their points against the 49ers in fourth quarters, however. The 49ers have allowed 27 fourth-quarter points in their three defeats this season. Their past eight opponents have scored only 104 points, or 13 per game, but they scored half of them in fourth quarters. Can the 49ers finish against the Steelers?
Riding the Marshawn Lynch train: Lynch rushed for 573 yards in 12 games with the Seattle Seahawks last season. He has 969 yards in 12 games this season. While Lynch managed only 44 yards on 17 carries against Chicago in his Seahawks debut last season, his hard-nosed running gave Seattle a needed edge in an upset victory. The way Seattle won that game -- with tough defense, a big back and an efficient quarterback -- showed how coach Pete Carroll envisioned winning games. Can the Seahawks do it again?
Nothing comes easy: The Arizona Cardinals are tied with Denver for the most games decided by seven or fewer points this season (10). Fifteen total point separated Arizona from its opponents in the four games won with John Skelton as the Cardinals' primary quarterback. The opponent this week, Cleveland, has played close games against the Cardinals' NFC West rivals. The Browns beat Seattle by three (6-3), lost to St. Louis by one (13-12) and played the 49ers relatively close in San Francisco (20-10). The Browns' likely starting quarterback, Seneca Wallace, started four games last season. Two were decided by a total of four points.
Shuffling lines: The St. Louis Rams head into their game against Cincinnati having started nine players on their offensive line, tied for second-most in the NFL this season. The Rams and Seahawks are the only teams in the league without any offensive linemen starting all games at the same position, according to ESPN Stats & Information. Seattle has weathered the turnover fairly well, but facing the Bears' Julius Peppers without injured left tackle Russell Okung could be problematic.