The 49ers top-ranked run defense not only has kept opposing rushers out of the end zone this season. It's kept meaningful runs to a minimum. The longest run of the year against San Francisco, 24 yards, was turned in by a quarterback, Michael Vick. The longest run by a running back? It was Roy Helu's 16-yard scamper on the first play of the game in Week 9 against Washington.
By contrast, Frank Gore has runs of 55, 47, 40, 27, 26, 25, 24, 21, 19 and 18 yards, and Kendall Hunter has broken off runs of 44, 26 and 17 yards.
Here's the week-by-week "longest run" tally for opposing tailbacks.
Week 1: Marshawn Lynch: 12 (WR Ben Obomanu: 13)
Week 2: DeMarco Murray: 8
Week 3: Cedric Benson: 10
Week 4: Ronnie Brown: 15 (QB Michael Vick: 24)
Week 5: LeGarrette Blount: 9
Week 6: Jahvid Best: 13
Week 8: Chris Ogbonnaya: 7 (QB Colt McCoy: 9)
Week 9: Roy Helu: 16
Week 10: Brandon Jacobs: 15
The 49ers have held opposing teams to a league low 73.2 rushing yards a game. The Eagles were the only team to even combine for more than 100 rushing yards. They had 108.
An additional note on holding opposing rushers out of the end zone: No team has done that throughout a full season. Three teams have held opponents to two rushing touchdowns in a season, but those marks were set when the league played only 14 games. Since then, the record is four rushing touchdowns in a season. That mark has been set by several teams, most recently by the Ravens in 2008.
The last runner to crash into the end zone against the 49ers? That was the Rams' Steven Jackson, who did it on a one-yard plunge in the first quarter of Week 16 last year.
-- Matt Barrows