One thing about the NFL playoffs seems obvious - the home field advantage is even more of an advantage in postseason.

The home team has won seven of the eight playoff games this season. In six of the eight games, the home team has covered the pointspread.So since last Sunday, the point spread on the conference championship games has gone up . . . and up . . . and up. The 49ers opened as 61/2-point favorites over the Giants and are now favored by 8 points; the Bills opened as 41/2 points over the Raiders and moved to 7 points, perhaps because Bo Jackson is doubtful for the game with a hip injury.

The home team is the home team because it had a better record during the regular season. Moreover, the 49ers beat the Giants at Candlestick this season (by four points) and the Bills beat the Raiders in Buffalo (by a deceptive 14 points).

Here's how Sunday's games shape up:

New York Giants at San Francisco

So here we are at the anticipated replay of that 7-3 Monday night struggle. Why are the 49ers favored by more this time - they were 31/2-point favorites the first time? Maybe because the Giants are missing Phil Simms and Rodney Hampton. Maybe because until last week's 31-3 blowout of Chicago, they hardly looked like a team that could make the Super Bowl.

But there are some pluses for New York. Like the words "new dimension," which in CoachSpeak means the scrambling ability of Jeff Hostetler, who is replacing Simms at quarterback and did so well against the Bears last week.

Less obvious is the return of Jumbo Elliott, the team's best run blocker, at left tackle. He didn't play in the first 49ers' game, cramping the running game.

It comes down to this:

Can the Giants hold San Francisco to seven points again? Can they hold Jerry Rice to one catch again? Doubtful.

But will the Giants move the ball better? Probably.

Bottom line: San Francisco will probably move within a step of its "ThreePeat."

49ERS, 17-13.

Los Angeles Raiders at Buffalo

Oh yes, the warm weather team at the cold-weather team. Although the Raiders have always played like the cold-weather guys, it's hard to imagine Howie Long or Bob Golic on a surfboard.

But can they stop the AFC's annointed team at Rich Stadium? They came close in October, leading 24-14 with 8:53 left before a series of blocked kicks and turnovers gave the Bills a 38-24 win.

One question here is the condition of Bo Jackson's hip. If he doesn't play, and that seems likely, it just means more carries for Marcus Allen, who did just fine with 140 yards against the Bengals.

A more pressing question is Jay Schroeder, the Raiders' quarterback.

The last championship game he was in was in 1986, when he was Washington's quarterback against the Giants. That one was replayed in a Giants Stadium gale and New York won 17-0.

The weather could be worse in Buffalo Sunday, and the pressure on Schroeder even greater if Jackson doesn't play.

BILLS 20-7.