After setting a franchise record by piling up 621 yards on the Buffalo Bills Sunday, the 49ers find themselves at the top of the heap in a number of NFL statistical categories. The most notable may be Alex Smith, who leads the league in quarterback rating through the first five games, Matt Barrows of the Sacramento Bee pointed out on Monday.

The running game has been as good as expected, with the Niners averaging 195.8 yards per game on the ground – best in the NFL. San Francisco also leads in yards per rush, gaining a whopping 6.1 each time they carry the ball.

The offense as a whole is among the league's best, putting up 401.2 yards per contest, good for 6th overall.

The defense is still doing its thing, as only the Seattle Seahawks have allowed fewer yards per game. The Niners are also tied for second in yards allowed per play, at just 4.5.

The combination of defense and offense has allowed the 49ers to get off to a 4-1 start. They will look to make it 5-1 when they host the New York Giants on Sunday.