The 49ers have managed to get pressure on the quarterback on 34 percent of plays, second in the league to the Bears, while blitzing less than any team except the Lions. That has contributed to seven interceptions, third in the league on a per-game basis.

Dee Ford (acquired in a trade with the Chiefs), DeForest Buckner and Arik Armstead are joined by Nick Bosa, the No. 2 overall pick in the 2019 draft, on a fearsome front line that already has a combined 12 sacks. Linebacker Kwon Alexander, added this season, and cornerback Richard Sherman, added last season, have also been crucial.

On the season, the 49ers have given up only 64 points in their five games, an average of 12.8. They are second only to the Patriots’ absurdly good 48 points in six games.

One knock against the Niners is that their five wins all came against teams currently .500 or below. That continues this weekend with a cushy game against the woeful Washington Redskins. Indeed, the team’s undefeated run has the potential to extend, as Washington is followed on the schedule by the beatable Panthers and Cardinals.

In Week 10, the N.F.C. West rival Seattle Seahawks could provide the first real test, but that game is in San Francisco. Based on current betting line trends, the 49ers could be favorites in every game except at the Saints in Week 14 and at the Seahawks in Week 17, by which time a playoff berth may well be secure. And on current form, the Niners seem hardly overmatched even in those games.

Most computer rankings have the 49ers either second or third in the league, behind the Patriots and perhaps the 4-2 Chiefs.

The bottom line is that a team that was 40 to 1 to win the Super Bowl before the season is now about 10 to 1.