Every Super Bowl is given an easy to remember handle by the press, and this year’s is “The AFC’s Best Offense vs. the NFC’s Best Defense.” Both halves of that tag are misleading, and both may be untrue.

First of all, the Colts only had the second-best offense in the AFC behind the San Diego Chargers, who outscored them by 65 points, though the Colts did lead the conference in yards gained. Second, the Bears did allow the fewest points of any NFC team, but that was largely because of a sensational first half performance in which they chased the memory of the 1985 Bears by giving up just 100 points. In the last eight games of the regular season, they gave up 155 points and were just another good defense — and in a couple of games they weren’t all that good.

If, as many believe, the Colts, when they are focused, really do have the AFC’s best offense, then a more accurate billing for this year’s Super Bowl would be, “The League’s Best Offense vs. a Pretty Good But Suspect Defense.” That’s really the crux of the matter. All other things being near equal, there are several factors that could make the difference.

The Colts, for instance, have had some severe lapses on special teams; if not for three poorly covered kicks against New England, they probably would have won in a blowout, and Chicago has very good special teams. Running offense and defense could make a difference, though, as is the case nearly every year, you could probably do a perfectly good Super Bowl analysis and leave rushing out of the picture altogether. Indianapolis ran the ball at exactly the league average, four yards a carry, and the Bears were slightly below that at 3.8. The Bears allowed exactly the league average on defense, 4.0, while the Colts defense was dead last in the league, allowing 5.3. That didn’t keep them from getting to the Super Bowl, and in any event, late season adjustments have plugged most of those holes, and the Indianapolis postseason rush defense did just fine.

But these issues are all sideshows. What’s it’s all going to come down to is how well Peyton Manning throws against the Bears defense, and, simply put, the prognosis for the Bears is not good.

There was a really sharp division in the Bears play between their first seven games and their last nine. Up to their October 29 meeting with San Francisco (which they won 41–10) Chicago was still fooling everyone with their creative coverages and blitzes, and the effectiveness of their defense enabled them to hide quarterback Rex Grossman’s deficiencies, namely a lack of accuracy and touch on short and middle-range passes. For those first seven games, the Bears looked like the best NFL team of the 21st century, averaging slightly more than 31 points per game while allowing slightly fewer than 10.

At that point, opposing defensive coordinators had analyzed most of Chicago’s tricks and diagnosed their weaknesses. From then on, they were only slightly better than mediocre; on November 5, they lost to the Miami Dolphins 13–31 and went 6–3 over the last nine weeks with two of the wins over Tampa Bay and Detroit, two teams that were 7–22 last season when not playing the Bears. And those victories were by a total of just eight points. For the first seven games, the Bears’ margin of victory was better than 21 points a game; over the last nine, it was just 2.2.

The unpleasant fact for Chicago fans is that in the Baltimore Ravens and the New England Patriots, the Colts have already beaten two teams whose defenses are as good or better than the Bears’ — possibly much better. (Both teams posted comparable or superior numbers in all the leading defensive indicators, and they did it against AFC opposition that was much stronger than what the Bears faced in their conference.) It isn’t likely on a dry, neutral field that the Bears are going to come up with anything that Manning hasn’t seen already several times this year.

The Colts are a funny team. This is probably the least formidable looking Indianapolis squad Tony Dungy has led in the last four seasons, yet, like the veteran Green Bay teams of the mid-’60s and the last couple of Pittsburgh Steelers teams to win the Super Bowl in the 1970s, they have penchant for rising above their statistics. They beat Buffalo by just one point, 17–16, while the Bears whipped the Bills 40–7; they slipped past the Giants 26–21 and the Jets 31–28 while the Bears beat the New York teams 38–20 and 10–0. Yet, they also beat a Miami team 27–22 that clobbered the Bears, 31-13, and they beat a New England Patriots team, twice (27–20 and 38–34), that beat Chicago (17–13). Indianapolis’s only real lapses came on December 3 and 10 when they lost back-to-back road games to Tennessee and Jacksonville by a combined score of 34–64; since then, they’ve addressed weaknesses in both their pass protection and run defense.

The Colts’ strong suit on defense is against the pass, which is more bad news for the Bears; they were second in the league in fewest yards allowed per game in the air, which means they don’t give up many long passes. Rex Grossman is wildly inconsistent and has shown no ability to read opposing defenses — during the regular season he had nearly as many interceptions, 20, as TD passes, 23. The Colts don’t have a great pass rush, though it did appear markedly stronger in the playoffs, particularly against the Patriots. They may not need one in this game if Dungy and his staff are able to confuse Grossman with coverages. Grossman’s real nightmare if the Colts take an early lead and he is forced to play catch-up, which will disrupt all Chicago’s game plans. If, on the other hand, the Colts slip behind early… well, you saw the second half of the New England game.

Rex Grossman is far from the worst quarterback in Super Bowl history, but he is definitely the worst quarterback in this Super Bowl, and that’s going to make all the difference.

The Pick: Colts

Mr. Barra is the author of “The Last Coach: A Life of Paul ‘Bear’ Bryant.”