By Mark Purdy
Mercury News Staff Columnist

There is no need to make reservations for San Diego. The 49ers will not win three football games this month. The 49ers are not going to roll through January like a freight train, or even a toy electric train. The 49ers are not going to be your next Super Bowl champions.

But they are going to win today.

Why shouldn't they? The 49ers are a division champion, playing a home game against a wild-card New York Giants team that just six weeks ago lost to the expansion Houston Texans.

Sounds like a 10-point victory to me.

But it is odd how quickly revisionist thinking takes hold in the NFL. When the 49ers clinched their division title, they were considered a very decent (but not great) team that, with a little luck, could do some playoff harm. But with the Candlestick Park advantage in the first round, the 49ers were considered a safe bet to reach the second round.

Then the postseason schedule was set. The 49ers' opponent was announced.

It turned out to be the Giants, who went on a nice little roll to win their final four games, the last a narrow victory against a Philadelphia team that didn't have a huge incentive to win.

Suddenly, the 49ers became the world's overdog darling. Everybody seems to believe they are set up to fail today. You would think the rest of the playoff field was luxury housing, while the 49ers were a crumbling shack on the wrong side of the tracks.

Check those real-estate listings again. If you look at the entire playoff map, the 49ers don't seem like such a bad part of town. In the NFC, outside of the Philadelphia Eagles, no team seems particularly fearsome. Green Bay was supposed to cause trouble, and you saw what happened Saturday. Tampa Bay still has no apparent means of offensive support. Atlanta is spectacularly inconsistent.

So maybe it is good that the 49ers are considered an average postseason bet. They deserve that label. Against other eventual playoff teams this season, the 49ers were 2-2. They lost to Philadelphia and Green Bay. They beat Oakland and -- hey, look here! -- the New York Giants.

Granted, that was way back in September. It was the opening night of the season. Both teams have changed. But the 49ers hardly played their best football that night, struggling to win 16-13 on a last-minute drive and a Jose Cortez (remember him?) field goal. If the 49ers who show up today are the same amped-up 49ers who showed up against the Raiders, aided greatly by the return of a healthy Zack Bronson on defense and Terrell Owens on offense, there's no reason to think they won't win.

And did I mention that the Giants lost to the Houston Texans?

Look, the East Rutherford ruggers deserve respect. They were 2-4 against eventual playoff teams this season, but they do present problems. The catch is, the 49ers appear to match up well against those problems. Tiki Barber is a major threat at running back. But did any running back destroy the 49ers this season? No, for the reason espoused by defensive coordinator Jim Mora.

``Our philosophy is you've got to stop the run first,'' Mora told writers last week, ``and we do a good job of stopping the run.''

That should happen again this afternoon, assuming that interior defensive linemen Bryant Young and Dana Stubblefield raise their intensity for the postseason. There's no excuse if they don't.

Jeremy Shockey, the Giants' outrageous tight end, is another obvious concern. But 49ers linebacker Julian Peterson is uniquely equipped to minimize Shockey's damage. He was held to three catches for 44 yards in the September game. And Peterson is not awed by Shockey.

``He has a lot of confidence in himself, but it can also hurt him,'' Peterson said last week. ``He'll get frustrated and then blow a couple of plays.''

At quarterback, the Giants' Kerry Collins is solid but not scary. The Giants have severe red-zone issues. In the 59 times they have been inside the 20-yard line this season, they have scored just 22 touchdowns.

Where could the 49ers break down? If cornerback Jason Webster can't go, he will be replaced by shaky rookie Mike Rumph, and you can only hope that the big-stage experience he had with the Miami Hurricanes the past few years will count for something today.

Stopping the Giants will be easier than scoring against them. But as long as 49ers quarterback Jeff Garcia remains upright, and as long as the 49ers running backs can get 4 or 5 yards when it matters, then you have to believe Owens will create a few highlights, with or without pompons.

Coach Steve Mariucci needs to let it all hang out a little more than normal on the play-calling, especially early, to get the crowd into the game and amp up his players.

But if it's close going into the fourth quarter, there's no reason to panic.

Garcia has shown he can move the team downfield in the clutch. For the record, the Giants were outscored 130-87 in the fourth quarter this season.

Also, did I point out that they lost to the Houston Texans?

Thanks to Atlanta's upset, it is actually possible for the 49ers to avoid playing in Philadelphia next week.

If they win today, they would go to Tampa Bay next week, and the Buccaneers seem far more beatable than the Eagles, so who's to say the 49ers won't make it to the NFC title game and . . .

Sorry. Just falling into the blather trap. The beautiful thing about playoff football is this: Heat always gives way to light. Always. This week, the heat has been everywhere for 49ers-Giants. The heat has been the fuss over Shockey, the speculation over Mariucci's job, the Jeremy Newberry comments about kicking certain parts of New York's anatomy.

The light comes on this afternoon: 49ers 27, Giants 17.

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