SANTA CLARA — As sour as the 49ers season has gone, they surprisingly lead the league in a positive aspect: fewest points allowed at home.
Hold your applause.
On the other side of the scoreboard, no team has scored less at home than the 49ers. That’s not a surprise considering how uninspiring and unproductive their offense has been, both near and far.
But the 49ers certainly have played different at home than away from Levi’s Stadium, which will host two of their final three games — Sunday against the Cincinnati Bengals and Jan. 3 against the St. Louis Rams — before Super Bowl 50 arrives Feb. 7.
“At home, you’re comfortable, you’re in your norm and you’re sleeping in your bed, for the most part,” linebacker NaVorro Bowman said.
At home, the 49ers defense bends, but opponents don’t break the 21-point barrier.
The Bengals (10-3) could change that. Looking to clinch the AFC North, they’ll deploy AJ McCarron for his first career start in place of injured quarterback Andy Dalton. They’ll also be without tight end Tyler Eifert, who shares the NFL lead with 12 touchdown catches but is out with a concussion.
“You think they would stay true to their offense, just plug and play them, and that’s what we’re prepared for,” safety Eric Reid said.
Reid and company will focus on shutting down A.J. Green (1,169 yards, eight touchdowns), Cal product Marvin Jones (666 yards, four TDs) and dual threat Giovani Bernard (647 rushing yards, 413 receiving yards).
The Bengals are 5-1 on the road, pumping out point totals of 33, 28, 34, 16, 31 and 37. Their lone loss came Nov. 22 at NFC West-leading Arizona, 34-31.
Though the Bengals are without Dalton and Eifert, the 49ers won’t be taking their opponent lightly, not after some veterans claimed that’s what happened last Sunday in a 24-10 humiliation at Cleveland. The 49ers defense gave up 481 yards to the Browns, including 54- and 50-yard runs that keyed two touchdown drives.
“An explosive run shouldn’t ever be any more than I’d say 10 or maybe 20 yards,” defensive coordinator Eric Mangini said in the following days.
The 49ers’ stat book describes a “big play” as a run of at least 10 yards and a reception of at least 20 yards. In going 3-3 at home, the 49ers have allowed 16 runs and 17 completions of the big-play variety. In their 1-6 road march, the 49ers have been nearly twice as generous with big plays, giving up 25 such runs and 33 receptions.
What’s most staggering is this: the 49ers run defense ranks second-worst in the league (133.2 yards per game). Yes, second-worst, not second-best. That unit has finished in the Top 10 annually since 2009, including No. 1 in 2011.
“We’re just learning,” Bowman said of a youth-laden defense. “All 11 guys have to know what’s going on in order to not be 31st and to be looked at as one of the elite run-stoppers in the NFL. We had a few guys this year who had room for error. As the year comes to an end, that room has been decreased.”
Coach Jim Tomsula blames a lack of cohesion among the defense’s front seven, stating: “We have to be able to finish each other’s sentences. We’ve got to be able to play together there.”
Once running backs get past that front line, they’re gaining more ground than ever. Mangini pointed to the secondary’s inexperience for why it hasn’t successfully funneled plays to create the “second level” wall.
“It’s part of this process with these young guys in terms of learning exactly where you fit and reading the different angles of insertion on the back,” Mangini said.
The youth movement has been mentioned by Bowman after losses throughout this season, and he brought it up again Friday in describing the “tremendous” difference between playing at home.
“You probably see a little immaturity, and that has to do with the performance on the road,” Bowman said. “You have to bring your own energy on the road. … It may have been new for a few guys on this team this year. I think they learned from it and hopefully they get better.”
The 49ers pass rush, meanwhile, has morphed from invisible on the road to efficient at home. Of this season’s 22 sacks, 16 have come at home. Of Aaron Lynch’s 6½ sacks, six have come at home.
If the 49ers pull the upset Sunday — they haven’t been favored in any game this year — they’ll likely have pressured McCarron and hindered his ability to deliver a big-play completion.
“If you get to him, it makes it hard for (McCarron) to get the ball to the receiver,” outside linebacker Corey Lemonier said. “We do have a big job in stopping the ball from getting to AJ.”
Stopped short of a Super Bowl trophy for a 21st straight season, the 49ers’ approach will be worth studying, especially at home and especially after last Sunday’s flunk-out in Cleveland.
Said Reid: “We need to step up and win these games to end the season on a good note.”
For more on the 49ers, see Cam Inman’s Hot Read blog at blogs.mercurynews.com/49ers. Follow him on Twitter at twitter.com/CamInman.
