Joe Theismann kept dropping back, then dropping from sight yesterday. Taking the wrath of a Dallas blitz, the Redskins quarterback was sacked seven times, losing 60 yards.

Why so many sacks? "All I know," he said, "are the end results."

The most pertinent end result at RFK Stadium yesterday was Dallas 24, Washington 10. As a team, though, the formerly unbeaten Redskins had it relatively easy. They fell to earth just once. Theismann crashed to earth seven times.

Naturally, the questions were put to the Redskins' offensive linemen. The Hogs, they call themselves. Before Dallas, the line had given up just 12 sacks, costing 87 yards. "We have a lot of pride," left tackle Joe Jacoby said.

Now, the Hogs also had a lot of explaining to do. Dallas, you see, was blitzing all afternoon. And the men hitching a ride on Theismann's back were different almost every time. Once it was strong safety Benny Barnes, another time it was left linebacker Mike Hegman, another time it was right linebacker Anthony Dickerson, another time right end Harvey Martin.

"Sometimes they blitzed the linebackers. Sometimes they blitzed the cornerbacks," Redskins center Jeff Bostic said. "And sometimes they blitzed both."

"A lot of times they came from the middle," Redskins tight end Don Warren said. "A lot of times they came from the outside."

"It was a little frustrating," Redskins left guard Russ Grimm said.

The most shameful, sackful moments came on the Redskins' final possession of the first half. Trailing, 7-0, with 1:06 left, the Redskins had first down on the Dallas 47.

Ed (Too Tall) Jones sacked Theismann for a loss of nine yards.

Hope. One play later, a 14-yard pass, Theismann to Joe Washington, the Redskins were at the Dallas 42.

Despair. Bethea sacked Theismann for a 14-yard loss.

Hope. Theismann completed a 15-yard pass to Art Monk and with 31 seconds to the half, they were back on the Dallas 41.

Despair. Safety Monty Hunter sacked Theismann for a loss of 10. Punt.

Tight end Warren said of the final sack of the half, "I blocked Harvey Martin and when my man (Hunter) saw me do that, he blitzed and got the sack."

This was perhaps the only sack-related explanation that came easily.

The Cowboys were overloading the strong side, where the tight end plays. "They would rush five-on-four, or four-on-three," said Bostic.

"And three blockers working against four (pass rushers) usually ends in a sack," Jacoby said.

While some fingers of blame prepared to butcher The Hogs, right tackle George Starke said, "People will see all of the sacks and say it's the offensive line's fault. But you can't pick on just one part of the offense. There are a lot of things a successful offense needs to do, like the quarterback picking up a safety blitz or like adjustments being made."

The Redskins linemen said they knew when the blitz was on. "When the linebacker comes running up to the line before the snap," Warren said, "you know he's coming."

Starke said the Dallas front four (a.k.a. Doomsday II) was not the problem. Bostic agreed, saying, "You'll notice on the sack list, most of the sacks were made by the linebackers and safeties. Dallas took chances. They left their cornerbacks one-on-one with our receivers. We could have made the big plays."

Theismann, on a day when the No. 7 on his back might have been a cruel notation of how many times he would be dumped, said of the Dallas defenders bent on dusting him, "They came hard and fast."