The Patriots are big favorites in today’s playoff game against Houston, but they know underdogs can bite.

Fifteen points.

That’s how much oddsmakers in Vegas think the New England Patriots will beat the Houston Texans by – at least – in Saturday night’s AFC divisional round playoff game at Gillette Stadium.

It’s one of the largest point spreads for an NFL playoff game in the past 50 years.

Maybe 15 points is a good place to start, considering the Patriots beat the Texans, 27-0, back in September – with third-string quarterback Jacoby Brissett making his first NFL start while Tom Brady was serving his four-game suspension.

Consider this, too: The Texans have never won a game at Gillette Stadium (0-4) and Brady is 5-1 against Houston (the lone loss coming in a meaningless contest on the final weekend of 2009 regular season, a game in which Wes Welker blew out his knee).

Frankly, the Patriots should win Saturday by 15 points. It shouldn’t be close. The top-seeded Patriots (14-2) are vastly better than the Texans, who won their division with a 9-7 mark and then beat the short-handed Oakland Raiders, 27-14, in a wild-card playoff game last weekend.

Yes, Houston enters the game with the top-rated defense in the NFL. But the Texans played six games against offenses ranked in the top 10 in scoring – New England, Oakland, Green Bay, San Diego, and twice against Indianapolis – and lost four of those games.

New England put up 27 points on Houston in Week 3 of the regular season without Brady (who’s back, in a big way), with Rob Gronkowski playing very little (he’s out for the rest of the season, of course) and with their passing game netting only 103 yards.

Yes, the Patriots should win easily on Saturday. But they’re not buying into any of that.

“It means absolutely nothing,” linebacker Shea McClellin said when asked about the point spread. “That’s only for people who bet.”

BETTING LINES MEAN NOTHING

You’re not going to get anyone on the Patriots to say anything other than that they expect a great game from the Texans. They expect Jadeveon Clowney and Whitney Mercilus to put on a ferocious pass rush. They expect cornerbacks A.J. Bouye and Johnathan Joseph to blanket every receiver. They expect quarterback Brock Osweiler to regain the form that earned him a stunning $72 million contract in free agency. They expect DeAndre Hopkins to show why he is considered one of the best wide receivers in all of football.

And if they need a reminder of how the underdogs can bite, the Patriots need only to look back at their own history to know betting lines mean nothing.

They won their first Super Bowl championship in 2002 by beating the St. Louis Rams, 20-17, in a game in which the Rams were favored by 14 points.

They lost two Super Bowls when favored against the New York Giants, including in 2008 when New England was favored by 12.5 points and trying to complete an undefeated season.

Vince Wilfork, the former Patriot who now plays nose tackle for the Texans, mentioned the 2008 Super Bowl and Clemson’s win over favored Alabama in Monday’s college football championship as examples of bad picks.

“So, it goes to show you what these experts know,” Wilfork said during a conference call with reporters this week. “One of the things is we don’t pay attention to outside, what people have to say about us or how good or how bad we are. I think this team is a close-knit group. We play well together and we keep everything as a family. We approach every game the same.”

‘NO ONE CARES WHAT YOU WRITE’

Wilfork knows of what he speaks. He began his NFL career in the Patriots locker room, learning the game from veterans such as Willie McGinest and Tedy Bruschi and Richard Seymour.

He knows that nothing that’s said or written outside the locker room has any place inside it. Apparently he’s trying to bring that attitude to his new team.

The newest Patriots learn that every year.

New England tight end Martellus Bennett, acquired in an offseason trade from Chicago, spoke about that this week.

“We don’t really care,” he said, when asked about blocking out the noise and distractions. “No one really cares what you guys write or what you guys say.

“We just believe in one another and what we have here and we never really listen to the outsiders because we know what’s true with what’s in here and in this locker room with the coaching staff and the work that we put in on the practice field.”

There are those who say the Patriots have a clear path to the Super Bowl in Houston on Feb. 5. They say that there isn’t a team in the AFC, or possibly the NFC, that can stop them.

Maybe. Probably. But the Patriots aren’t making any parade plans just yet.

“It’s the NFL,” McClellin said. “Everyone has great players. It’s a matter of who plays best that day.”