Just one month ago, the Giants stood between the New England Patriots and history. The Giants played their best game of the season, but the Patriots came back from a 10-point deficit, won the game 38–35, and became the first team in NFL history to finish the regular season 16–0.

The Giants took the momentum from that game and rode it on an improbable run through the postseason. In Super Bowl XLII, they get a second chance. A Giants win won’t just stop New England from making history as the NFL’s first-ever 19–0 team. It will also make history as the greatest Super Bowl upset of all-time.

Yes, that’s correct: the greatest upset, bigger than Broadway Joe’s guarantee or the last-second win over St. Louis that launched the current New England dynasty. The regular-season gap between these two teams is the greatest in Super Bowl history. The Patriots set an NFL record, outscoring their opponents by 19.7 points per game. The Giants outscored their opponents by just 1.4 points per game, the third-lowest figure of any team to ever make the Super Bowl. A win would make the Giants only the second Super Bowl champion to finish the regular season at 10–6.

The Giants believe they’ve left that mediocre regular season behind them, and there is no doubt they have played markedly better in the postseason. Still, it isn’t like this is the first team in NFL history to get hot in the playoffs. Out of the 10 teams that have required three wins to make the Super Bowl, the 2007 Giants beat their playoff opponents by the smallest combined point total.

WHEN THE GIANTS HAVE THE BALL

How did the Giants go from a mediocre wild card team to NFC Champions in the span of four weeks? The Giants aren’t any better stopping the pass, and they’ve only improved slightly against the run. Their ground game is actually gaining fewer yards a carry. The difference is almost entirely the passing game, especially the performance of quarterback Eli Manning.

Starting with the final regular-season game against New England, Manning has been dramatically more accurate. In his first 15 games, he completed just 55% of his passes; in the last four games, his completion rate is 64%. During the regular season, he led the league in interceptions. In three playoff games, he has not thrown a single one.

Conventional wisdom says that Manning has improved by “taking what the defense gives him,” rather than trying to force the big play when it isn’t open. That’s true, somewhat, but don’t confuse “taking what the offense gives him” with “dumping the ball underneath.” Manning is throwing more midrange passes, and fewer short ones.

In the first 15 games of the year, 47% of Manning’s passes were short (five yards through the air or fewer) and only 32% were mid-range (6 to 15 yards through the air). In the past four games, Manning has thrown 39% short passes, and 45% mid-range passes.

Giants offensive coordinator Kevin Gilbride is also calling fewer deep passes, and the ones he does call are of a different nature: curls and outs that sacrifice yards after catch for a higher completion percentage.

The Patriots gave up a season-high 35 points to the Giants when these teams first met, but the Giants only scored on one of their last four drives. The Patriots improved by switching to the one weakness Manning does not seem to have conquered over the last four weeks: the big blitz.

Manning has improved significantly against four or five pass rushers, but he still has problems if the defense sends six or seven. Over the last four weeks, Manning averaged 7.3 yards per play against four pass rushers and 6.2 yards per play against five, but just 4.3 yards per play against six or more. In the first Patriots-Giants game, the Patriots sent six pass rushers only once in the first half, but six times in the second half. On those seven plays, Manning completed three passes out of six, with a sack, for a net average of 0.7 yards per play. (The last Patriots big blitz did result in a three-yard touchdown pass to Plaxico Burress, which made the game 38–35.)

Until the postseason, the Giants offense was far better on the ground than it was through the air, and that ground game certainly did not disappear when the passing game became more accurate. The Giants are particularly strong running up the middle, which has often been a weakness of the Patriots defense this season. The Patriots also have trouble against smaller, more agile backs, and they did not have to face big-play threat Ahmad Bradshaw in the first game against the Giants.

WHEN THE PATRIOTS HAVE THE BALL

There are a lot of reasons why the Giants almost beat the Patriots in the final game of the regular season, but very few of them have anything to do with defense. The greatest offense in NFL history still scored on seven of their nine drives.

A good defense will take away what the offense does well, but that’s impossible with the Patriots, because they do everything well. In the playoffs, San Diego and Jacksonville concentrated on taking superstar receiver Randy Moss out of the game — but if you double-team Moss, you can’t blitz quarterback Tom Brady. If you do try to blitz Brady, you’ll leave slot receiver Wes Welker wide open. And if you just hang back to play zone, protecting against the big play, the Patriots will hand the ball to Laurence Maroney, who has averaged 5.2 yards a carry over the last five games.

Even if you get to pick your poison, it is still poison.

The one positive the Giants can take out of the first game is that they forced the league’s best red-zone offense to kick field goals by stopping them before they even got to the red zone. The Giants have struggled near the goal line all year, and that has not changed in recent weeks. New York’s last four opponents marched past the 18-yard line a total of 10 times. Eight of those drives ended in touchdowns, two in field goals. To keep the Patriots out of the red zone, the Giants have to get stops against the league’s best third-down offense. But over the past four weeks, while everything else was going right for the Giants, their defense on third downs deteriorated significantly.

During the regular season, the Giants allowed a third-down conversion rate of 35%, fifth in the NFL. However, over the last four weeks, the Giants have allowed a third-down conversion rate of 49%. That would have been the worst figure in the league during the regular season.

The Giants’ pass rush was a major reason why the Giants’ defense was so strong on third down during the regular season. The Giants led the league in sacks, and were one of just three teams with more sacks on third down (27) than first and second downs combined (26). Of course, the Patriots also have one of the league’s top offensive lines — they allowed just 21 sacks, fifth in the NFL — and the Giants have yet to face that line with its starting five intact. Right guard Stephen Neal and right tackle Nick Kaczur missed the first Giants-Patriots game, but will be healthy this Sunday.

SPECIAL TEAMS

Domenik Hixon’s kickoff return for a touchdown was important in keeping the first game close, but it was an aberration. It was the only kickoff the Giants returned for a touchdown all year, and the only kickoff return touchdown the Patriots allowed all year.

If both teams play more like they did the rest of the year, the Patriots will get a major field-position advantage from the kicking game. Stephen Gostkowski is one of the top two or three kickoff men in the league, averaging 64.5 yards per kickoff this season. The Giants’ Lawrence Tynes averaged just 61.8 yards per kickoff. With the thin Arizona air giving Gostkowski’s booming kickoffs even more distance than usual, Hixon may not even get many chances to touch the ball.

Broadcast announcers will assuredly mention that Giants punter Jeff Feagles holds the all-time NFL record for punts that land inside the 20-yard line, and there’s no doubt Feagles is better than the Patriots’ Chris Hanson. However, the Giants had poor punt returns all season, so neither team really has an advantage in the punting game.

NEW YORK AND THE GHOSTS OF PATRIOTS PAST

Over the past two weeks, many observers have compared the Giants and the Patriots — not this year’s Patriots, but the Patriots from six years ago. The 2001 Patriots were 14-point underdogs against the St. Louis Rams, but they slowed down the “Greatest Show on Turf” and pulled off a shocking 24–21 upset. Now the Patriots are the juggernaut with a high-scoring offense, and the Giants are the scrappy underdog trying to prove they belong on the big stage.

However, there is another Patriots team comparable to this year’s Giants: the 1985 Patriots. That was the first team in NFL history to win three road playoff games on its way to the Super Bowl, a feat the Giants duplicated this year. That team was also led by a promising but inaccurate first-round quarterback, Tony Eason. Eason threw 17 interceptions during the regular season, but just like Eli Manning, he went three straight postseason games without a turnover. Like the Giants, the 1985 Patriots were massive underdogs against one of the greatest teams in NFL history. The Chicago Bears crushed them 46–10. Eason did not compete a single pass.

Most likely, the Giants won’t pull a shocking upset like the 2001 Patriots, and they won’t get blown off the field like the 1985 Patriots. Instead, they’ll end up like a third team from New England’s Super Bowl past: the 1996 Patriots, a good team outclassed by a great team. The Patriots kept Super Bowl XXXI close for a while, but in the end, the Green Bay Packers were simply better, and they won by two touchdowns. This year’s Patriots will probably dispatch the Giants in a similar fashion, completing their historic 19–0 season.

Mr. Schatz is the editor in chief of FootballOutsiders.com