The Seahawks have one less day of rest than the 49ers and one less day to prepare. They played Monday night. Plus they fly on Saturday. All of this will have an impact.
The 49ers are desperate. Don't underestimate desperation.
If the 49ers lose this game, there is a good chance they will fall behind the Cowboys or the Eagles in the wild-card race at least for one week, maybe permanently.
But even if the Seahawks lose, they easily can lock up the No. 1 seed in the NFC with wins against bad teams down the stretch. They already clinched a playoff spot. The 49ers haven't clinched anything. The Seahawks have less to play for than the Niners.
The 49ers typically play well at Candlestick against the Seahawks. The Seahawks haven't beaten the 49ers at Candlestick since 2008. History is on the 49ers' side.
Last season at the Stick, Frank Gore ran right up the gut of the Seahawks' defense for 131 yards. The Seahawks put eight and sometimes nine defenders right in front of the 49ers' offensive line to stop Gore, but they couldn't stop him. Mike Iupati, in particular, had a great game. He bulldozed defenders, especially in the second half. It was the best game of his career.
Most of Gore's big runs came on "wham" and "trap" plays. The Seahawks have an aggressive, fast defensive line that wants to charge into the offensive backfield. They're great at doing this in Seattle on fast fake turf and with that loud home crowd.
But the 49ers use this aggression against Seattle in San Francisco. Think of the trap play. You've heard of the trap play. An over-aggressive defensive lineman rushes into the 49ers' backfield looking to hit Gore. The Niners' offensive lineman let him do it. As the unsuspecting lineman chargers full speed ahead, an offensive lineman decks the defender from the defender's blindside. Big hole for Frank Gore. Thank you very much.
The wham play is similar, except the fullback or the tight end cracks the defender with the blindside block.
The 49ers are not so good at whamming and trapping in Seattle, but they are terrific at home. And this is a big advantage for the 49ers.