IRVING, Texas -- When the Dallas Cowboys convened this past Wednesday to begin preparing for their "Monday Night Football" game against Washington, the team's five starting offensive linemen walked into the locker room to find large white boxes sitting in their lockers.

Inside were new iMac desktop computers, bought by running back DeMarco Murray as an unsolicited gesture of thanks to the men who helped him become the first player in NFL history to rush for 100 yards in each of the first seven games of the season.

"He gave them to us and said, 'Thanks. It's been a great year. Let's keep it rolling,'" rookie right guard Zack Martin said.

Things are undoubtedly rolling in Dallas.

In one of the biggest surprises of the season, the Cowboys are tied for the NFL's best record at 6-1. They lead the NFL in rushing, with an average of 159.7 yards per game. They have the league's leading rusher in Murray, who has gained 913 yards in seven games and is on pace to become just the eighth NFL back to top 2,000 rushing yards in a season.

Prior to the season, many observers predicted Dallas' depleted defense could rank among the worst in history. But given the way the offense controls the clock by keeping the ball on the ground, it has been good enough.

That is why, sitting in his office at Valley Ranch last week, Cowboys executive Stephen Jones was smiling. The plan, concocted after quarterback Tony Romo broke his clavicle midway through the disastrous 2010 season, has worked.

"That's when we said, 'Look, if we don't start helping this offensive line, we're going to get our quarterback killed. We're not going to be able to run it. We're not going to be able to throw it, because we can't keep him up,'" Jones said. "'It's going to take time, but we've got to start the process.'"

Playing behind a dominant offensive line, DeMarco Murray has rushed for an NFL-best 913 yards. Matthew Emmons/USA TODAY Sports

The process necessitated an organizational shift in philosophy. Before 2011, the Cowboys had never used a first-round draft pick on an offensive lineman during Jerry Jones' ownership of the team. Those picks, when Jones didn't trade them, usually were reserved for skill positions.

"We knew we were in a rough spot," said Stephen Jones, who serves as the team's chief operating officer and director of pro personnel. "The offensive line needed to improve. We were getting old."

Four of the team's five starters in 2010 were more than 30 years old. Right tackle Marc Colombo was "fighting for his life," Jones said. So was left guard Kyle Kosier.

Elite pass-rushers have their hands full with Tyron Smith, the Cowboys' first-round pick out of USC in 2011. Tim Heitman/USA TODAY Sports

Then-offensive line coach Hudson Houck identified the player he wanted in the 2011 draft. It was Southern California tackle Tyron Smith. Opinion was split in the building. Some liked Colorado tackle Nate Solder. Others liked Boston College tackle Anthony Castonzo. But Houck liked Smith, who at 6-foot-5, was shorter than Solder or Castonzo but had longer arms -- a trait Houck valued. Plus, Houck was a USC guy, having both played and coached there. He knew Smith had a great work ethic and would do whatever his coaches asked. He also had 4.7 speed and a frame that could hold more than the 280 pounds he carried in college.

"My grade was really high," Houck said. "It was almost embarrassing."

When projecting players, the Cowboys use a sliding scale. Can the prospect be a Pro Bowl player? Will he just be a serviceable starter? Will he be only a backup?

"The level I said was in two years he'd be in the Pro Bowl," said Houck, who retired after the 2011 season. "I was a little lucky, but in two years he was in the Pro Bowl."

The Cowboys picked Smith ninth overall in 2011 and started him all 16 games at right tackle. In 2012, they flipped Smith to left tackle, moved veteran Doug Free to right tackle and signed undrafted rookie Ronald Leary, who became the starting left guard last season.

In 2013, Dallas wanted to draft another guard in the first round, but by the time the Cowboys were set to pick at 18, the two they wanted -- North Carolina's Jonathan Cooper and Alabama's Chance Warmack -- were already off the board. They traded down by swapping first-round picks with San Francisco and acquiring the 49ers' third-round pick. Then they selected Wisconsin center Travis Frederick with the 31st overall pick.

BY THE NUMBERS A statistical sampling of the Cowboys' offensive line entering Week 8: • Dallas' top unit has been together for 86 percent of the team's snaps. Only the Cardinals (99.7 percent) have had their top group on the field for a higher percentage this season. • Cowboys QBs have been pressured (sacked, under duress or hit while throwing) on just 20 percent of dropbacks this season. That figure ranks No. 5 in the league and is the team's best mark since 2010. • The Cowboys average 4.7 yards per rush inside the tackles, which ranks fifth in the league. • Dallas is one of seven teams to average at least 3.0 yards before contact per rush up the middle this season. -- ESPN Stats & Info

Hours before this year's draft began, with the reconstruction of their offensive line almost complete, Stephen and Jerry Jones reviewed strategies for the first round. If one of the right defensive players were available at No. 16, they would go that route. If not, they would target another offensive lineman. But what if Texas A&M quarterback Johnny Manziel was still available?

Jerry Jones told Stephen: "We don't need to worry about it. He's not going to be there."

"He could be there," Stephen replied to his father. "Let's go over it again."

As it turned out, Manziel was there. Stephen called what transpired "the great debate" -- whether or not to draft Manziel.

"The one quarterback that was in debate, he's a pretty interesting guy," Stephen said. "He's a great competitor. But I always tell people, if Jerry didn't want to make that pick, we wouldn't have picked Zack Martin. At the end of the day, Jerry was good with it."

The rookie out of Notre Dame has started all seven games at right guard this season. With four starters under the age of 25 -- at 30, Free is what offensive coordinator Bill Callahan calls "the old man" -- the rebirth of the Cowboys' offensive line was complete.

"All the pieces have come together," Callahan said.

Said Houck, "When you have an offensive line and runners as good as they have right now, it protects the passer better, so the passing game becomes better. Because now you're holding onto the ball longer, it protects the defense. And when you can run the ball like they're running the ball, then you run down the [opposing] defense. I don't want to be overzealous, but I enjoy watching them play, and I think they're the best team in the NFL right now."

Dallas' O-line has kept Tony Romo upright and, more importantly, healthy after his back surgery. Matthew Emmons/USA TODAY Sports

They seemingly do everything together. Once a week, usually on Thursday, the offensive linemen go out to dinner. They worked out together in the offseason. They come in for treatment together on their days off. Before games, they take the field as a unit.

"It's kind of old-school ball, where guys have really taken a liking to each other," Callahan said. "They enjoy each other's company and are true pros. They have a lot of fun -- I know that."

When Frederick got married in March, multiple members of the O-line made the trek to Wisconsin for the ceremony. He and Smith share an agent, Joe Panos, who played guard and tackle at Wisconsin when Callahan was the Badgers' offensive line coach in the early 1990s.

Callahan said the characteristic that connects Dallas' offensive linemen is their intelligence, and they remind him of the offensive line he coached with the New York Jets that included Alan Faneca, D'Brickashaw Ferguson, Nick Mangold and Damien Woody.

"Those [Jets linemen] developed a real close bond," Callahan said. "They're all smart guys. They were more experienced and were much more mature than this group, just because of their understanding of the game and their ability to communicate with one another and, obviously, they performed at a high level.

"Those [Jets] are great guys, and these [Cowboys linemen] are great guys, impeccable character guys, and you've got to have that. I like high-character guys up front that really have a passion for the game and care about each other and what the game means and play for each other. And these guys do."

Their affinity for each other is genuine.

"We like hanging out," Frederick said. "We like being with each other. That's really important. Now, we know each other better than we ever have. It makes it so much easier on the field to communicate, because you don't always have to say every single word. They know what you're going to do. They know what you mean. They know what your body language is saying, so you don't always have to say those words, and that makes everything so much easier."

Former O-line coach Hudson Houck sees similarities between the 1990s O-line and this year's unit. James D. Smith/USA TODAY Sports

It's blasphemy in Texas to compare any Cowboys team to the ones that won three Super Bowls in four years during the 1990s. Yet given the way Murray has run the ball against every team he has faced this season -- including Seattle and San Francisco -- given that Dez Bryant is one of the premier receivers in the league and given how effectively Romo has been playing, similarities can be drawn.

None of it would be possible without the franchise's commitment to investing first-round picks on offensive linemen in three of the past four drafts.

"I think there is a parallel," said Houck, who coached with the Cowboys during the Super Bowl seasons. "They've got three first-round draft picks on the offensive line, which was not the case in the '90s. Other than that, they talk about the '90s, and they talk about Michael Irvin, a great quarterback and a great runner, the threesome. And they have that right now, a great quarterback, great runner and great receiver. And they've got a great offensive line.

"This team is so solid and so well coached, I just think they're going to get better every week because they're still fairly young."

Stephen Jones acknowledged there is an offensive comparison to be made. But this Dallas defense, while it plays hard, does not have the level of talent those Cowboys teams had.

"It's too much for this young team," Jones said. "I mean, they're not there yet, in my mind. That's nice of Hud to say, but we've got a long ways to go before you compare. That's one of the greatest teams the league has ever seen. You're talking about, this is the third-youngest team in the NFL that's just kind of getting a little confidence finally. We'll see what they've got."

What they've got now is one of the best offensive lines in the game, and that has helped improve almost every facet of the team. With Free sidelined by a broken right foot, Jermey Parnel has filled in ably.

This Cowboys team, for once, looks like it's for real.

"We all felt on edge coming into this season, and I think people thought we were going the other way, not above 8-8," Jones said. "In my mind, we don't have to reset our goals. You just feel like, hey, we've got a real shot to achieve some of the things we're after.

"But I will say this: After what we've been through, there's nobody taking anything for granted around here, and everybody knows it could stop tomorrow. We've had our share of disappointments around here."