Baltimore Ravens quarterback Joe Flacco passes in the first quarter against the Pittsburgh Steelers, Saturday in Pittsburgh. The Ravens are 7-4 on the road in the playoffs in their 19 years as a franchise.

BALTIMORE — Say this for the Ravens with John Harbaugh coaching and Joe Flacco throwing the passes: they have upended the usual math of the NFL playoffs.

The league’s best teams toil all year, trying to ensure they’ll play at home in January. They do so knowing home teams have won 67 percent of all playoff games in the Super Bowl era.

But in a seven-year run the likes of which the NFL has never seen, the Ravens have not only played 11 road playoff games, more than any other team. They’ve won seven — or 64 percent.

They’ve done it in some of the league’s most unwelcoming venues — Denver’s Mile High Stadium, Pittsburgh’s Heinz Field and Gillette Stadium, where they’ll try to upset the top-seeded New England Patriots once again Saturday afternoon.

In just 19 seasons as a franchise, the Ravens have amassed as many road playoff wins as any team in league history. They are the NFL’s ultimate road warriors.

It’s an unusual distinction. You won’t find a Raven who’d rather play Saturday’s game in Foxborough, Mass., than Baltimore. As several players noted this week, the Ravens have faced all these road games in part because of unwanted letdowns in the regular season.

Nonetheless, the Ravens’ ability to play their best under the most challenging circumstances has won them widespread admiration.

“Most of the time, they’ve walked in as the underdog,” said CBS analyst and former Steelers coach Bill Cowher. “And John has played that card as well as anybody. . They’re a scary team to face right now.”

In searching for explanations, start with the simplest — the Ravens carry as many proven stars as any team they might visit. Nothing mystical about that.

Said Flacco: “We’ve obviously had a lot of chances at it, a lot of experience with it, and reacted well in it just because — just like I always go back to — we’ve had a good football team around here, and guys that are strong and not intimidated and very confident in nature. I think it just plays well.”

He’s a big part of it, having performed as well in the playoffs as any quarterback in the NFL. In addition, defensive centerpieces Terrell Suggs and Haloti Ngata have started 16 and 15 playoff games, respectively. Marshal Yanda, the anchor of the offensive line, has started 11. All receive universal praise from opponents, including the Patriots.