I’m sure most football fans reacted as I did Sunday when they switched on the New England-Indianapolis game and saw a field more conducive to ice hockey. That’s it, I thought, the Colts start this game behind 10-0. They’re going to be playing catch-up all day.

The Patriots are a better team than the Colts on any field, but they’re not as much better as they looked during their 20-3 win last Sunday. In the first game of the season, on a dry field, the Colts played the Pats to a 24-24 tie in regulation, then lost on a field goal in overtime – the precise margin of the Patriots’ home-field advantage. The difference between that game and last week was the difference in field conditions, all of which worked to the Patriots’ advantage.

New England loses that very sizable advantage in the AFC Championship Game. At Heinz Field, where conditions this Sunday may be even worse than they were in Foxboro last Sunday, the Steelers are the best home team in the NFL; during the regular season they were 8-0, allowing just 104 points. On the road, the New England Patriots are just another good team, 6-2, allowing 155 points.

Yet, the Patriots are a three- or four point pick, depending upon which line you go by. Why, exactly? Out of respect: They have won two of the last three Super Bowls and are on the verge of establishing a mini dynasty. But there isn’t any clear reason why they should be favored in Sunday’s matchup. In fact, all of the small indicators – and when two teams this good are fighting for a berth in the Super Bowl, all indicators are small – favor Pittsburgh.

Let’s start with defense, which is where the Steelers started when they restructured their team after last year’s 6-10 season. The Pats were tough on the run, allowing 3.9 yards per rush; the Steelers were better, allowing 3.6. New England was very good against the pass, allowing just 6.3 yards per throw. Pittsburgh was even better, allowing just 5.9.

The two defenses have similar strengths, built around terrific linebacker corps; mobile, versatile linebackers; and hard-hitting secondaries. But in James Farrior, Pittsburgh’s defensive MVP, and Troy Polamalu, the Steelers have, respectively, the best linebacker and the best safety to suit up Sunday. (The two have nine interceptions between them.)

The running games are a wash, with the Pats’ Corey Dillon and Kevin Faulk having slightly more speed than the Steelers’ Jerome Bettis and Duce Staley, who have a little more power. All have proven they can run well on bad fields.

In any event, these teams aren’t where they are now because of their running backs. Both Bettis and Dillon had strings of six straight seasons with over 1,000 yards rushing, and neither played on a Super Bowl contender till they were on teams with good passing games and good defenses.

The Steelers averaged 4.0 yards a rush this season, the Patriots 4.1, both slightly under the league average of 4.2. If one of the these teams jumps to an early lead, say 10 or 14 points, then the running backs on that team will get the ball often. The question is, which team is likely to get that lead. I think it’s Pittsburgh.

Looked at over the course of the season, the Steelers’ and Pats’ quality passing stats look pretty even – until you eliminate the first two games, which Ben Roethlisberger didn’t start. After that, in terms of sheer efficiency the comparison goes the Steelers’ way. Tom Brady gained 1,071 more yards and threw 11 more touchdowns, but he had to throw 179 more passes to get them. In the most important passing statistic, yards per throw, Roethlisberger was 8.9 to Brady’s 7.8.

But in light of what the Pats did to Peyton Manning, one has to wonder how Roethlisberger will deal with Bill Belichick’s defense. The Pats didn’t attempt to put much pressure on Manning, and in fact did not sack him at all, generally dropping as many as eight men downfield to cover the passing routes.

Against Pittsburgh, Belichick will probably choose to blitz more, partly because the Steelers don’t have as dangerous a package of wide receivers and partly because, after all, Roethlisberger is still a rookie and at least theoretically subject to being rattled.

He certainly seemed nervous last week against the Jets, but his bad thumb hampered his throwing all day and was probably responsible for the uncharacteristically bad throws on those two interceptions. On the assumption that the thumb has healed, don’t be surprised to see Roethlisberger challenge the Patriots’ secondary when he thinks he’s got single coverage on his wideouts, particularly Plaxico Burress, who averaged a team-high 20 yards per catch this year.

As for Brady, he didn’t look great last Sunday against a not too imposing Indianapolis defense. The key was that Brady didn’t have to look all that good for New England to win. This week he will have to, and against much tougher opposition, and against a defense that is at least and possibly more physical than his own. Roethlisberger doesn’t have to play a great game; he merely has to play a better one than Brady.

Do I like a rookie quarterback’s chances against such formidable defensive veterans? No. But I didn’t like Jake Delhomme’s chances in last year’s Super Bowl against New England either, and the unheralded Panthers QB riddled the Patriots pass defense for 323 yards and three touchdowns.

Earlier this season, the Steelers astonished the football world by dominating the teams with the two best records, the Patriots and the Eagles, in successive weeks. It’s doubtful that Pittsburgh will once again rush for 221 yards to New England’s 5, as they did in that game (Corey Dillon was out of the Pats lineup). But Pittsburgh will have the same blockers who allowed zero sacks of Roethlisberger, and the same defense that held Tom Brady to a field goal.

The Steelers are now where the Patriots were three years ago when they pulled their sensational upset over the St. Louis Rams. Actually, they’re a little better than the Patriots were then. And they’re younger, hungrier, and at home. I’ll pick the Steelers by six.