Although it’s not a totally foreign concept, it’s rare that a conference championship game, like Sunday’s AFC clash between the Patriots and Ravens at Gillette Stadium, is a rematch from the title contest the season before.

In fact, since the NFL-AFL merger in 1970, only seven times has there been an AFC or NFC title game involving the same teams from the previous season. Working in the Patriots’ favor: On five of those occasions, the team that won the previous matchup also took the sequel.

The Patriots beat the Ravens a year ago in the AFC Championship game, 23-20. They’re favored to win Sunday, and advance to Super Bowl XLVII in New Orleans. That the same opponent stands in their way makes for an interesting subplot, but they’re too preoccupied thinking about now than to put much stock in what took place then.

“I said at the beginning of the week, we have a lot of respect for that organization,” coach Bill Belichick said on Friday. “They win a lot of games, they’re in the playoffs, they win playoff games. We’ve had some great battles with them; we’ve won some, they’ve won some, most of them have come right down to the wire, very competitive. They’re a tough, hard-nosed football team that’s hard to beat, and we respect that challenge.”

Until Sunday, the Patriots have never been part of an AFC Championship game rematch. Four of the previous seven year-after repeats have taken place in the AFC, three in the NFC. The most recent was in the 1994 season. Also working in the Patriots’ favor (or the Ravens’, for that matter): Six of the seven teams that won the conference title rematch went on to capture the Super Bowl.

On this Championship Sunday, as we get ready for the eighth, do you think you can come up with the first seven rematches? Here’s a refresher course. Years listed are season, not calendar year.

1971: Cowboys 14, 49ers 3 (NFC)

A year after beating the 49ers in San Francisco (17-10) and advancing to Super Bowl V, the Cowboys picked off three John Brodie passes and won a defensive struggle in the first-ever playoff game at Texas Stadium. Roger Staubach only threw for 103 yards, but he added 55 on the ground. Two weeks later, Dallas beat Miami in Super Bowl VI, the last meaningful game the Dolphins would lose for 20 months.

1975: Steelers 16, Raiders 10 (AFC)

The reigning Super Bowl champion Steelers made it two straight wins over Oakland in the AFC title game, and two weeks later made it two consecutive Super Bowl titles, beating the Cowboys, 21-17. Against the Raiders — this time the game was in Pittsburgh — Franco Harris rushed for 79 yards and a TD, and the Steelers held on after Oakland recovered a late onside kick.

1976: Raiders 24, Steelers 7 (AFC)

One week after beating the Patriots, 24-21, in controversial fashion, Oakland finally earned sweet revenge against the Steelers after two AFC title game losses. Quarterback Ken Stabler was efficient, throwing for only 88 yards on 10 completions, but two went for touchdowns. The Raiders defense limited the Steelers (who were without injured running backs Franco Harris and Rocky Bleier) to 237 yards, and forced the game’s only turnover.

1979: Steelers 27, Oilers 13 (AFC)

Houston upset the top-seeded Broncos to set up an unlikely rematch, but Pittsburgh once again had the answer for Oilers running back Earl Campbell to advance to Super Bowl XIV, which it would win over the Los Angeles Rams, giving them four titles in a six-year stretch. To get there, the Steelers held Campbell (1,697 rushing yards to lead the NFL) to just 15 yards on 17 carries. Terry Bradshaw (18 for 30) threw for 219 yards and two scores.

1987: Broncos 38, Browns 33 (AFC)

A season removed from beating the Browns with a 98-yard, John Elway-led drive, Denver benefited from a late fumble by Earnest Byner to rip Cleveland’s heart out once again. The Browns appeared ready to take the lead, but Byner fumbled at Denver’s 2-yard-line with just over a minute left. The Broncos advanced to their second straight Super Bowl, but would be overmatched yet again, this time by the Redskins, 42-10.

1993: Cowboys 38, 49ers 21 (NFC)