By Tony Massarotti, Globe Columnist

If history is any indication at all, the AFC Championship almost certainly will go the distance. The New England Patriots and Baltimore Ravens have played four times in the last five years, and not a single one produced a relatively easy Patriots victory.

That is why a win on Sunday would mean more to the Patriots than any win they have had in four years.

Here we are again, Boston sports fans, in that tense purgatory between victory and defeat. Remember what this feels like? Whatever the point spread, the outcome is in doubt this time. Beginning on Nov. 21, the Patriots have played a succession of inferior opponents that they absolutely, positively should have beaten, games that lined up on their schedule like a list of menial household chores.

Do the dishes. Fold the laundry. Get groceries. Pick up the dry cleaning. Take out the garbage.

But now the Ravens are coming, and we all know what Baltimore is capable of. At least we should. In 2007, with New England chasing an undefeated season, the final score was Patriots 27, Ravens 24 in nothing short of a great New England escape. In 2009, the Ravens were seemingly on their way in for a game-winning touchdown when Baltimore wide receiver Mark Clayton dropped a fourth down pass deep in New England territory of an eventual 27-21 Patriots win. Then came Baltimore's 33-14 dismantling of the Patriots in the divisional playoffs at Foxboro. Then came last year's 23-20 New England victory in an overtime game that marked the return of Patriots receiver Deion Branch.

Total cumulative score: Ravens 98, Patriots 91. New England won three of the four games, though all three victories effectively came down to the final possession.

Get the picture? Expect a close one. When these two teams have met, the games have been both competitive and combative, adjectives that would describe any worthwhile competition in just about any sport.

That's why we watch.

As usual, we all have our opinions on how this game will unfold. None of them mean a blasted thing. (For what it's worth, I like the Patriots to the tune of something like 27-23.) Based on recent history, there is every chance that Baltimore running back Ray Rice will rip up the Patriots on the ground as surely as Tom Brady could shred the Ravens through the air. Baltimore quarterback Joe Flacco has had his moments as surely as BenJarvus Green-Ellis. Maybe Matt Light will deftly handle Terrell Suggs. Maybe Suggs will abuse him. Maybe the Ravens will get to Brady and maybe they will not, though it is likely that each sideline will make the necessary adjustments so as to keep at least some balance in check.

You see what we're getting at here? Don't be foolish by expecting a blowout on either side. The players and coaches on these teams are simply too good. When the Ravens defeated the Patriots in the playoffs two years ago, New England's receiving corps operated without Wes Welker (injured) and included such luminaries as Sam Aiken, Chris Baker and Julian Edelman.

For the Patriots, all of that makes Sunday's game an opportunity to prove that they are indisputably back, at least close to being the team they were at the beginning of this millennium. In recent years, for one reason or another, they have simply stalled. Brady got hurt. They lost to the Jets. They had a creampuff schedule. Every year has brought some obstacle the Patriots have been unable to overcome, regular season and postseason success failing to align at the same time.

If we're being honest about this, last week's win over the Denver Broncos really did not tell us much. How the Patriots performed was far more worthy of our praise than the outcome, particularly on defense. But we all know that Denver faced the Buffalo Bills in Week 16 and got mercilessly walloped by a 40-14 score, Buffalo's only win in its final nine games.

Is that the Patriots' fault? Of course not. They earned the No. 1 seed because they had no real lapses, finishing 13-3 and earning a favorable draw as a result. Had the Ravens similarly held serve against relative door posts like Jacksonville, Seattle or Tennessee, Sunday's game would be in Baltimore. Instead, it will be played here in New England, where the Patriots can secure their footing among the NFL's truly elite.

Years ago, when the Patriots were winning Super Bowls, New England's ability to perform at the critical moments is what separated the Patriots from everyone else. With time dwindling and broadcaster John Madden calling for the Patriots to take a knee in Super Bowl XXXVI, Brady drove the team down the field and set up Adam Vinatieri's game-winning kick. The Patriots' dynasty was instantly born, New England thumbing its nose at the doubters and second-guessers while winning three Super Bowls in four years.

In the nearly eight years since their last title, the doubt has slowly seeped back toward Foxborough, the Patriots losing to the Indianapolis Colts in the AFC Championship, to the New York Giants in the Super Bowl, to the Ravens and Jets in the earlier rounds of the playoffs. Along the way, we have wondered whether the Patriots can beat the good teams when it matters anymore, wondered whether they can execute when it matters most, wondered if they can reclaim the aura and feeling that made them the most clutch situational team in football.

Only the Ravens now stand between the Patriots and the answer, between New England and a trip to the most celebrated event in sports.