The Ravens need to run the ball. The Tennessee Titans can't afford to let them.
Ravens running back Jamal Lewis has carried the weight of his team's eight-game winning streak. Over that time, he has rushed for 944 yards, accounting for 45 percent of the Ravens' total offense.
The Titans' run defense has become the barometer of the team's success.
In the final two months, Tennessee's only two losses have come when the defense has allowed a running back to gain more than 62 yards.
Lewis ran for 99 yards in the Ravens' 24-23 victory over the Titans on Nov. 12. Jacksonville's Fred Taylor rushed for 104 yards as the Jaguars upset Tennessee, 16-13, two weeks later.
During the Titans' six wins in November and December, they held Washington's Stephen Davis to 62 yards, Pittsburgh's Jerome Bettis to 42 yards, Cincinnati's Corey Dillon to 42 and Dallas' Emmitt Smith to 20.
Lewis was on a tear during the second half of the season.
In his past eight games, he has produced 90 yards rushing seven times. The rookie will start his 16th game of the season Sunday after never playing more than 12 in each of his three years at the University of Tennessee.
"We invested the fifth pick in him, so obviously we thought a lot of him," Ravens coach Brian Billick said. "He's been phenomenal. You kept waiting for that midseason slump to where he was going to have to drag himself through practice or maybe fall off a little bit from one point to the next. We haven't seen it.
"He's worked through that as a rookie and obviously he's the strength of what we do offensively."
That may mean Lewis might have to work overtime against the Titans. After averaging 23 carries in the final eight regular-season games, he carried 30 times for 110 yards against the Broncos.
In playoff history, teams are 31-0 when they have a running back total at least 30 carries.
It's a formula that the Ravens won't dispute.
"We're in the playoffs. So you ride the horse that's going," Billick said. "If that means Jamal has to carry it 40 times, he'll carry it 40 times. You have to feed the stud in playoff time, and he's our stud."