The Dallas Cowboys and New England Patriots have watched plenty of film of each other. They've pored over their own playbooks, probing for ways to gain an advantage.
That's fine, but there's nothing like facing each other on the field to get a real feel for their strengths and weaknesses.
And that hasn't happened in four years.
"We've got a crash course going here on the Cowboys," Patriots coach Bill Belichick said. "I think this would be a lot easier team to prepare for if you were playing them twice a year."
Instead, they've met 10 times in 51 years since 1960 when Dallas entered the NFL as an expansion franchise and New England started as a charter member of the AFL.
Sunday's game will be the first between the teams since 2007 when both were 5-0 before the Patriots, behind Tom Brady's five touchdown passes, won 48-27 en route to an undefeated regular season. They finally lost in the Super Bowl to the New York Giants.
Both teams are much different now. The Patriots (4-1) have six active players who were on the 2007 team. Jason Garrett is in his first full season as coach of the Cowboys (2-2).
"We don't know each other that much, but we're kind of going into the game the same way. We both have the same kind of look at each other. Certainly, they've been a marquee franchise in this league for the last decade," Garrett said. "They're a team that everyone in this league has studied over the last 10 years, so even though we haven't played them, we've watched them. ... Hopefully, we can gain some advantage that way."
They may need it to control Wes Welker, who leads the NFL with 45 catches and 740 yards receiving. And running back BenJarvus Green-Ellis is coming off a career-high 136-yard rushing performance in last Sunday's 30-21 win over the New York Jets.
But the Cowboys have the stingiest run defense in the league and will be rested after a bye week. They are 16-6 after having a weekend off and have won their last five road games following a bye.
The Patriots have their bye after Sunday's game and don't want to go into the break with a loss.
"You never want to lose one," guard Logan Mankins said, "but that would make it tough."
The Cowboys will have cornerback Orlando Scandrick back from a high ankle sprain that sidelined him for all but the opener. He generally covers the slot receiver, Welker's position.
"It's the fastest team we've played this year," Belichick said. "You look at plays and you stop the film and you say, `Looks like this is going to be a good play,' and then it just collapses. ... They haven't given up very many plays, period, run or pass."
They did in their last game, a 34-30 loss to the Detroit Lions in which they squandered a 24-point, third-quarter lead and Romo threw two interceptions that were returned for touchdowns.
"You never want that to happen," said Romo, who may have better luck Sunday against the NFL's lowest-ranked defense. "You have to minimize turnovers in key situations. We did that for two of the games and two of the games we didn't."
Brady had a different problem against the Jets. He was sacked four times and the pressure is likely to continue against DeMarcus Ware, one of the best pass rushers in the NFL, and a defense tied for eighth in the league with 13 sacks.
"He doesn't let the pressure rattle him. His composure is not like any other quarterback," Ware said. "You've got to do some things on defense to take them off kilter."
Brady has thrown six interceptions, but four came in a 34-31 loss at Buffalo. The Patriots have one fumble all season, but recovered it.
"They are always doing everything right," Ware said.
Not quite, but they have won 19 straight regular-season games at home and scored at least 30 points in the last 13 regular-season games, one less than the record set by the St. Louis Rams in 1999-2000.
The last team to hold New England below that total was Cleveland in a 34-14 win last Nov. 7. Rob Ryan was the Browns' defensive coordinator, a position he holds now with the Cowboys.
That gives them some extra insight into the Patriots, although Ryan is coaching different players.
"If you have an experience where you played against a team before, you certainly go back and watch that game to see if there is anything that continues to relate to what that offense or defense is doing," Garrett said. "I think we get more focus on what's happening in 2011."
The Patriots knowledge of the Cowboys could get a boost from defensive end Andre Carter, who faced them 10 times in the last five years as a member of the Washington Redskins.
"I have made a few pointers," Carter said, "but I just think as regards to our study, we've been just dead on, constantly learning what they're trying to do."
Both teams did plenty of preparation for each other long before this past week.
"It wasn't like we walked in here (last) Monday morning and were like, `Who are we playing this week? Let's go to work on them,' " Belichick said.
But once the game starts, both teams must adjust to what the unfamiliar players on the other side of the line of scrimmage are doing.
"They change their scheme based on who they're playing," Belichick said. "What we get and what they did last (game) are probably two different things."