ESPN College Football

With a stingier defense than last season's championship team, Alabama is in command of its BCS title hopes.

Coach Nick Saban, however, expects his top-ranked Crimson Tide to be tested during Saturday night's visit to rival Tennessee.

As expected, Alabama (6-0, 3-0) was atop the initial BCS poll and its continued success at stifling opponents has greatly contributed to that ranking. The Crimson Tide lead the nation with averages of 7.5 points and 181.2 yards allowed after giving up 8.2 and 183.6 per game, respectively, in 2011.

They're also yielding 55.3 rushing yards per contest -- a significant improvement from 72.2 last season. Alabama gave up only three yards on the ground and 129 overall in last week's 42-10 win at Missouri.

Those improved performances have come despite the loss of seven starters, including three NFL first-round draft picks.

"It's been a hard-working group," Saban said. "They've had a really good attitude about what they want to try to do. I still think there's a lot of areas that we need to improve on."

Alabama could use those improvements because it faces three ranked teams -- No. 15 Mississippi State, No. 6 LSU and No. 20 Texas A&M -- after traveling to Knoxville. The Crimson Tide coach, however, knows his team can't also overlook its visit to Neyland Stadium.

Tennessee's offense is ranked in the top 25 nationally with 482.3 yards and 38.0 points per game, and Tyler Bray has thrown for an SEC-best 16 touchdowns. The junior also has 1,730 yards, second-most in the conference behind Arkansas' Tyler Wilson.

"We're going to be challenged in a way that we've never been challenged by the quality of the offensive team that we're playing this week in their capabilities in the passing game as well as the balance they have running the ball," Saban said.

Alabama has won five straight in the series, including a 41-10 victory in Knoxville on Oct. 23, 2010. Current starting quarterback A.J. McCarron passed for a touchdown and ran for another score as the Crimson Tide piled up 31 unanswered points during a 37-6 home win Oct. 22.

Alabama's chances of extending its dominance might hinge on not only stopping the Vols' offense but also exploiting a historically woeful defense by Tennessee standards.

With former Alabama linebackers coach Sal Sunseri in his first season as defensive coordinator, the Vols (3-3, 0-3) are giving up 31.5 points per game, their worst average since allowing 42.7 in a six-game 1893 season. They're also yielding 429.9 yards per contest, the worst showing since the school began recording that statistic in 1950.

"We're not very good right now," coach Derek Dooley said. "You are what your film is. We don't get off blocks the way we need to up front. We don't get enough hats to the football."

Tennessee, which has lost 14 straight to ranked teams, has given up a combined 129 points in its three games against Top 25 foes this season but 60 in its other three games.

The Vols, though, were competitive in some of those high-profile matchups, losing 51-44 at then-No. 5 Georgia on Sept. 29 and 41-31 at then-No. 19 Mississippi State this past Saturday. They held a 14-10 lead over then-No. 18 Florida on Sept. 15 before giving up 27 second-half points of a 37-20 defeat.

"We've got a lot of games left," outside linebacker Jacques Smith said. "We've got a lot of ball left. We determine our destiny as a football team. I know we're going to get the job done."

Alabama's win streak in the series is its longest since a seven-game run Oct. 18, 1986-Oct. 17, 1992. The Crimson Tide, who lead the series 48-38-7, are also seeking a third consecutive win in Knoxville.