Here's what we learned about the Redskins based on yesterday's season-opening victory against the Cardinals: nothing.

The Redskins ran up 347 yards and scored 31 points. An average offensive play gained a whopping 7.2 yards. No turnovers committed. Mark Rypien was efficient. So was the running game. The play calling was imaginative and completely unpredictable. The defense pitched a shutout. A supposedly suspect pass rush produced three sacks. Cardinals receivers were rarely open, and the Redskins intercepted four passes.

All in all, you'd have to be a nit-picking fool to find fault with anything the Redskins did at RFK Stadium yesterday.

However . . .

The opponents were the Phoenix Cardinals. You know how meaningless NFL preseason games are? Beating this particular Phoenix team is about a half-step higher than a preseason victory. Poor Joe Bugel. His reward for building one of the best offensive lines in NFL history is to rebuild perhaps the most wretched, forlorn franchise since Tampa Bay entered the league as an expansion team.

His quarterback, Timm Rosenbach, is essentially a rookie; yesterday was his second NFL start. The backup is somebody named Tom Tupa, also with little experience. Three of his top four running backs are rookies. The offensive line gave up 20 sacks in the preseason. The defense is so bad the club signed Carl Hairston, who will be 38 before the season is over, to rush the passer. The only way this could have been worse was if the game had been played in Arizona, where about 20,000 people might have shown up in Saudi Arabian heat. If you're ranking the quality of NFL franchises from 1 to 28, the Cardinals are fighting Bullet Bob Irsay's Colts for dead last.

Asked what he said to his old buddy Buges after the 31-0 drubbing, Joe Gibbs said: "Hey, there's not much you can say. I think I said something like, 'It takes awhile.' "

Asked what Bugel said in reply, Gibbs thought Buges said "Thanks." For what? Buges didn't say, but it might have been for not running up the score to 73-0, which might have been a possibility.

As eager as we had been for the season to start, we've got one more week to wait. As Charles Mann said when asked if he felt the questions about the pass rush had been answered, "It's still a question."

Wilber Marshall, who was in the Cardinals' backfield more than rookie running back Anthony Thompson, cautioned somebody who wanted to make a big whoop-te-doo over yesterday's blowout. "Wait a minute, we can't count this for much," he said. "The Cardinals, they're just starting out. The test is next week. Sure, winning this game is important in that you want to start the season with some momentum and a team needs to get that feeling of winning if it is going to be successful. . . . But the test is next week. We'll be playing a proven team, the proven team that's been there and been there."

That team, in case you've had your We-just-take-them-one-at-a- time game face on, is the two-time defending Super Bowl champion San Francisco 49ers. The real season will commence next Sunday at Candlestick Park, 4 p.m., Eastern time.

"You'd like to think if we play as well as we did today we can beat anybody," Mann said. "But they're the world champions. We'll have to play with this kind of intensity to come close."

Anyone who has worked as hard and slept in the office as many hours as Gibbs did last week has earned the right to feel different than outsiders. He said throughout training camp that it is important for this team to get off to a good start. So, a loss to a team as hapless as the Cardinals would have been an utter disaster. The first thing the really good teams have to do is beat the patsies, and you don't get any patsier than Phoenix. Besides, the Redskins have had too many bad starts to take anything for granted.

"Any win in an opener for us is a good start," Gibbs said. "They made it tough on us. They did a lot of things in the first half that made us adjust."

Surely you didn't expect Gibbs to say, "We just steamrolled the poor suckers, didn't we?"

Speaking of adjustments, how about that three tight-end alignment that produced the first touchdown, a 37-yard pass from Rypien to wideout Ricky Sanders. One might suspect Gibbs went to a play Buges had never seen. Not exactly. The Redskins had run it a few times, but not much.

When you have Art Monk, Gary Clark and Kelvin Bryant standing shoulder to shoulder on the sideline and three tight ends in the game, you almost have to think "run" if you're a Phoenix defender. As one of those tight ends, Jimmie Johnson, explained, "It's a great way to keep all our big people in the game, not let you substitute and still do something the defense doesn't expect."

Johnson and Don Warren were split wide, with Ron Middleton also in the lineup. Sanders was in the slot on Johnson's side. All of sudden, the Cardinals' run defenders were confronted with a passing situation. One safety took Johnson, leaving a linebacker -- Ken Harvey -- to cover Sanders. Very funny. Rypien spotted the mismatch, and in seconds the score was 7-0.

Buges shook his head. He had seen the Redskins start slowly (0-2 last year, both games at home) and brought his team here hoping for another sluggish season-opening effort by Washington. That's not what he got. Gibbs took the blame for the previous slow starts, saying, "It's my fault that we didn't seem to start well."

There was no blame to shoulder yesterday, only credit to share. But when the videotape starts showing images at Redskin Park this week, it won't be difficult to separate the Cardinals from the 49ers, or from most other teams in the league for that matter.

Asked what he will tell his team about next week's opponent, Gibbs said, "I don't think I need to tell them anything."