San Francisco's top-ranked run defense has yet to allow a rushing touchdown through the first 11 games of the season. The all-time record for fewest rushing touchdowns allowed in a season is two, which has been set by three teams. Since the NFL adopted a 16-game schedule in 1978, 11 teams have allowed four rushing touchdowns in a season. Credit for the 49ers' success is given to a front seven that features Patrick Willis and NaVorro Bowman at inside linebacker, and Justin Tackle at defensive tackle. Safety Donte Whitner believes the run defense success is more about tenacity than talent. "If you have guys that are just going out there and saying, 'I'm going to just do my job and that's it, I'm not going to do extra, I'm not going to help cover for the next guy,' then you're going to have holes in the defense," Whitner said. "We have a bunch of guys that when they get up there on the defensive line and the linebackers, they have guys coming to block them and they're just beating blocks, and that's how you do it. It's not about the scheme, it's about the will to beat the block and make the tackle. Do you have it or don't you?"