Three-point stance: San Francisco 49ers

The Patriots play host to a second prime-time game in as many weeks Sunday night when the 49ers visit.

49ersLike Houston, San Francisco brings a defense brimming with impact talent and a consistent running game. Linebackers Patrick Willis and NaVorro Bowman are centerpieces of a formidable unit that ranks among the league’s best against both pass and run. The addition of Colin Kaepernick under center has added a dimension to San Francisco’s offense, already capable of running the ball.

A win puts San Francisco in the playoffs, and an accompanying Seattle loss also awards the Niners a division title.

Here are three areas to watch for on Sunday:

1. Pressure's On: Sunday brings another tall task for the offensive line. The 49ers’ defense features a dominant duo along the line of scrimmage in outside linebacker Aldon Smith and defensive tackle/end Justin Smith. In his second season in the league, Aldon Smith is three sacks shy of Michael Strahan’s single-season record. His 33.5 career sack total through two seasons is an NFL record since 1982 (when sacks became official). Teammate Justin Smith is a disruptive force as well, and the play of those two is a big reason why San Francisco doesn’t commit extra defenders to the pass rush. The 49ers send four or fewer rushers on 80.0 percent of dropbacks, the fifth-highest rate in the league. San Francisco excels at both getting to quarterbacks (league-most 30 sacks) and defending passes (5.9 yards per attempt allowed, second in NFL) with just a four-man rush. Veteran safeties Donte Whitner and Dashon Goldson are fast and physical, pacing a capable secondary that will offer more resistance than the Texans did last Monday.

2. The X Factor: Colin Kaepernick is the only real question mark in the 49ers’ lineup. His early returns have been positive, with a 3-1 record in four starts. Kaepernick has flashed big-play ability both throwing and running, though he has been conservative since his first start against the Bears. Kaepernick’s average throw traveled 10.2 yards downfield in that game, and he finished 16-of-23 for 243 yards, two touchdowns and no interceptions. In the three starts since, his average pass has been 6.7 yards downfield, and he’s averaged 208 passing yards per game with a touchdown and an interception combined. His considerable mobility adds another dimension to San Francisco’s offense. Kaepernick leads all NFL quarterbacks with 9.1 yards per rush and four touchdowns on option rushes this season. Kaepernick has a 50-plus yard rush in each of the last two games, the first quarterback to have multiple runs that long since Randall Cunningham in 1990 according to Elias.

3. Ground Control: San Francisco is very strong on both sides of the running game. The 49ers’ defense has allowed only six rushing touchdowns over the last two seasons, with the next-closest team allowing 11 (Texans). San Francisco tackles very well, with a 1.2 yards after contact per rush allowed average that rates as lowest in the NFL, and an improvement on their league-best 1.5 average from a year ago. Offensively, only four running backs with at least 100 rushes have a better yards-per-rush average than Frank Gore (4.9) this season. A big part of San Francisco’s success comes from quality offensive line play. The 49ers have three former first-round picks on the line, including starting tackles Anthony Davis and Joe Staley, and the 49ers’ 3.64 yards before contact per rush average ranks second in the league.