SANTA CLARA, Calif. -- The San Francisco 49ers -- after losing back-to-back games by a total of four points -- are suddenly a long shot to make the playoffs.

Stunning, right?

Two weeks ago, the 49ers were coming off the bye at 6-2 on the strength of a five-game winning streak. Now, they are 6-4, and mathematically speaking, on the outside of the playoff chase.

According to NumberFire, the 49ers have a 35.7 percent chance of making the playoffs as a wild-card entry with six weeks left. The 49ers are behind Detroit and Chicago, both also 6-4, in terms of playoff percentage. The Lions' chances are 77.2 percent. The Bears' chances are 54.5 percent. Arizona, also 6-4, is at 18.8 percent.

The 49ers’ chances being so low is a bit surprising. They have the seventh easiest remaining schedule in the NFL and their final six opponents are a combined 27-34. The 49ers are 4-0 against teams with losing records and 2-4 against winning teams. The only teams with winning records remaining on the 49ers’ schedule are Seattle (Week 14) and Arizona (Week 17).

Plus, this is a good team. Perhaps they will completely blow up and fall apart. I just don’t see that happening. The defense played playoff-caliber football in the losses to Carolina and New Orleans. As long as the defense holds up, the 49ers will win games.

Yes, the offense has struggled, but it scored at least 31 a game during the five-game win streak. So, the potential for offensive success is there.

I’m no mathematical genius (I topped out on multiplication), but 35 percent seems low. If I had to put a number on the 49ers making the playoffs I’d go around 75 percent.

Practice squad signee: The 49ers signed rookie safety Dax Swanson to the practice squad. He is from Sam Houston State and was with the Colts in camp.