The most puzzling statistic in the NFL this season belongs to the San Francisco 49ers, who are 6-1 at home, 0-7 on the road — and out of the playoffs because of it.

“We’ve been looking for that answer all season long,” quarterback Jeff Garcia said Sunday after San Francisco lost 41-38 at Cincinnati. “Somehow, we need to show up on the same page on the same day.”

The discrepancy is glaring, and it might make home-field advantage even more important than usual in the postseason, where hosts are 38-12 over the past five years.

New England, for example, had not allowed a touchdown at home in four straight games until Jacksonville scored a meaningless TD with just over three minutes left Sunday. Right now, the Patriots (12-2) hold the home-field advantage in the AFC, which gives them a clear route to the Super Bowl.

St. Louis (11-3) will almost surely get at least one home playoff game and could get home-field advantage in the NFC. The Rams are 7-0 at home, 4-3 on the road.

The 49ers won’t be playing anywhere once the postseason begins because of their problems away from San Francisco.

In seven home games, San Francisco has allowed just 82 points — fewer than 12 a game. On the road, the 49ers have given up 203 points — 29 each time out.

But it has to be more than the crowd.

Oct. 12, the 49ers beat visiting Super Bowl champion Tampa Bay, 24-7.

San Francisco running back Kevan Barlow, front, fumbles as he is tackled by Cincinnati's Mark Roman. The 49ers are out of the playoff hunt because they are 0-7 on the road.

The next week, San Francisco went to Arizona and lost, 16-13 in overtime, in a half-filled stadium where the 49ers had as many fans (or more) than the home team. Two weeks ago, in the return match at Candlestick, the 49ers beat the Cardinals, 50-14.

And that came a week after San Francisco lost, 44-6, in Baltimore.

The 49ers aren’t the only team that is markedly better at home.

After Sunday’s games, visitors are 85-138 this season, a .383 winning percentage. Last season, visiting teams finished 107-148-1, or .420.

Some examples:

• Seattle is 7-0 at home, 1-6 on the road. The home record keeps them in pursuit of a wild-card playoff spot, and the road record kept them from a shot at the NFC West title.
• Baltimore, tied with Cincinnati for the lead in the AFC North, is 6-1 at home and 2-5 on the road, including a loss Sunday at the Raiders (4-10).
• Detroit, admittedly a bad team, is 4-3 at home. But the Lions are 0-7 on the road and tied the NFL record for consecutive away losses at 23 when they were routed 45-17 in Kansas City.
• Arizona, another loser, has all three of its wins at home and has played three other tight games, including a last-second 20-17 loss Sunday that allowed Carolina to clinch the NFC South.

Nobody really knows why there are such big swings for teams.

“I always played my best games on the road — before I got here,” says Arizona’s journeyman quarterback, Jeff Blake, who has been with the Jets, Bengals, Saints and Ravens during a 12-year career. “Maybe it’s a mental thing.”

The Cardinals won’t be in the playoffs. Nor will the 49ers.

Even if they were, they wouldn’t last long.

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Top to bottom: Peyton Manning joined elite company Sunday when he threw five TD passes in Indianapolis’ rout of Detroit. He had six touchdown passes Sept. 28 in New Orleans, so Sunday’s performance made him just the fifth quarterback since the AFL-NFL merger in 1970 to have two games with five or more TD passes in one season.

The others: Jim Kelly, Dan Marino, Dan Fouts and Warren Moon.