Just six weeks ago, ESPN assembled 64 NFL experts to project outcomes for the 2014 season. The group had amassed hundreds of years collectively covering football, making it well versed in the league's annual truth: Every year, a team ascends from nowhere into a serious contender for the Super Bowl.

On cue, this expert panel almost entirely dismissed one of the league's most prominent franchises as a possibility for that role. ESPN Insider KC Joyner was the only participant to predict a playoff berth for the Dallas Cowboys, whose 5-1 start has made them the biggest surprise of the 2014 season. Advanced Football Analytics projected the Cowboys to lose four of their first six games, Westgate Las Vegas SuperBook assigned them 75-1 odds to win the Super Bowl, and there was plenty of sentiment that they were headed to a fourth consecutive 8-8 season.

So, where did we go wrong? What have the Cowboys done to surpass such mediocre expectations? And have they set a structure for sustainable success all season? For those answers and more, we turned to a cross section of the original panel for a roundtable discussion.

NFL Nation writer Kevin Seifert: What informed your initial impression of the Cowboys this summer? What did you think would be the issue?

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Senior NFL writer John Clayton: Defense, defense, defense. That was the big thing I looked at on paper, as we all did in the offseason. It wasn't necessarily based on performance, because you don't have a chance to see the team until the regular season. I looked at them as having their best two defensive linemen coming off injuries. Anthony Spencer had microfracture surgery and Henry Melton had an ACL. The rest of the guys were just journeymen, and you wondered how they were going to get a pass rush.

Then, the first day of offseason practice, their best defensive player -- Sean Lee -- blows out his ACL. So you looked at it and said, "How can this thing improve, and have they really added anything to help?" I always thought they would have a good offense, but I thought they would lose a lot of 27-24 kind of games.

Seifert: The funny thing, John, is that we could make a decent argument the Cowboys' defense hasn't outplayed its expectation as much as everyone is giving it credit for. It's true their opponents are scoring about six fewer points and gaining about 73 fewer yards per game this season as compared to 2013, but there is an easy explanation.

The Cowboys' offense has increased its average time of possession per game by nearly six minutes, from 29:01 to 34:42, according to our friends at ESPN Stats & Information. In turn, Cowboys opponents have been on the field less and have run about 12 fewer plays per game. In reality, opponents are averaging the same number of yards per play -- 6.1 -- against the Cowboys this season as they were in 2013.

We'll get to the reasons for that increased time of possession in a bit. For now, however, let's stick with the Cowboys' defense. Did we underestimate its personnel? Is it being used better by defensive coordinator Rod Marinelli? Or has it just not been exposed yet?

ESPN scout Matt Williamson: I, like most, thought linebacker Rolando McClain was done. He had shown very little to this point to believe otherwise, but he deserves all the credit in the world for resurrecting his career.

I still think the overall defensive talent here is subpar, but they are being coached extremely well. They rarely make mental mistakes. They do their job and operate their given responsibilities. And they get to the ball carrier in droves. As well as any defense in the league, the Cowboys get many tacklers to the ball.

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ESPN Dallas columnist Jean-Jacques Taylor: It all starts with Marinelli. He has made a simple defensive scheme even simpler. The Cowboys weren't allowed to so much as change the defensive call the first couple of weeks, and Marinelli demands the players play as hard as they can every snap. A lot of coordinators and coaches say that, but they don't all demand it every play -- even in practice. Teams that play all out every play can hide some of their flaws simply with effort.

It sounds bad, but losing cornerback Morris Claiborne for the season has helped the defense. Orlando Scandrick, the starter, and Sterling Moore, who's now the nickel corner, are much more physical against the run and better at holding the edge when teams attack the perimeter. They're each considerably better than Claiborne in coverage, especially when it comes to deflecting passes.

Seifert: Marinelli might well be maximizing the Cowboys' defensive talent, but it wouldn't matter if the Cowboys hadn't finally committed to the run game. Keeping this defense off the field is undeniably part of the Cowboys' early success.

But the hiring of Scott Linehan, who most recently spent five seasons calling plays for the pass-happy Detroit Lions, provided no immediate indication that a philosophical change was imminent. Part of me wonders if this was a well-executed plan -- or if Jerry Jones & Co. just stumbled into a record-setting hot streak from running back DeMarco Murray.

DeMarco Murray is leading the league in rushing attempts and yards, but he has a history of injuries. Joe Nicholson/USA TODAY Sports

ESPN NFL writer Ashley Fox: For as much abuse as Jones has taken over his franchise's inability to climb out of mediocrity or do anything in the postseason since Troy Aikman retired, I think it would be unfair not to give him some credit for this. I think the most important thing that happened was taking the play-calling responsibilities away from Bill Callahan (while convincing him not to walk) and hiring Linehan to be the new playcaller.

Between Linehan and Jason Garrett, the Cowboys have emerged committed to the run, and Murray, to his credit, has been spectacular. I do wonder if Dallas' defensive issues will bite them in the end.

Taylor: Linehan made it clear they were going to run the ball this season, and they were going to spend the offseason and training camp preparing to do it. They demoralized their defense in training camp with their ability to run the ball, and it continued in the preseason. When Murray became the first runner in 17 games to crack 100 yards against the San Francisco 49ers in the opener, they knew they could run it against any team.

Garrett also knew that with Romo's back issues -- he had two surgeries in 2013 -- and a shaky defense that he needed to keep off the field, a strong running game was the best way to do it.

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Seifert: But can this running game be sustained through the whole season? Murray has never made it through a 16-game season uninjured. He missed three games in 2011, six in 2012 and two last season.

Clayton: I don't know where they'll find the help, but they've got to lighten his load. He's on pace to have more carries than anyone in NFL history. Six weeks into the season, and he's already got 159 carries. That's 26.5 per game.

You can maybe hold that for a little while longer, but one of two things will happen to him. He'll either use up everything he has this year and not have anything in the future, or he's going to get hurt. They've got to take it easier and lighten his load. It's not like he doesn't have a history of injury. That part of the equation I don't think they can sustain.

Williamson: He has always been talented and always produced -- when healthy. That is the kicker. Of course, his offensive line is among the very best in the NFL, and the Cowboys are obviously sticking with their running game. So, in turn, his numbers are skyrocketing and he is producing at a rare pace. But I have serious doubts whether his body can continue to withstand such a massive workload.

Clayton: What I think that we didn't anticipate was that Murray would get off to one of the best starts in NFL history and take pressure off everyone. Then they could go and apply physical football and not have to play as much defense as they would have had to. On paper, you couldn't see that. On paper, you saw Murray never put together a string of seven consecutive games where he's been healthy. No one could know that he would put up six 100-yard games. That changed the equation.

Seifert: Of course, if there is any slip from Murray or the running game, the Cowboys will be right back where they started: with Romo as the centerpiece of the offense. Is there any reason to think he can handle the full load if it is thrust back on him?

Fox: Until he proves otherwise, that will always be a question Romo will hear. For his career, Romo is 15-21 in December and January regular-season games and 1-3 in the playoffs, with his lone win coming against a Philadelphia Eagles team that would trade its franchise quarterback four months later. As good as he's been in the month of November, Romo hasn't been clutch down the stretch of seasons.

Scott Linehan's run-first play calling has lifted a burden off Tony Romo's surgically repaired back. Jim Brown/USA TODAY Sports

Seifert: So what do you think? Are you now ready to admit the Cowboys have built a sustainable paradigm for success? Will they win the NFC East or do you think we're going to end up having been right all along?

Taylor: The Cowboys have had really good offenses in previous years, but this is the best offense they've had because it travels. They can play this style in the cold, in the rain, in the heat, at home or on the road.

This style is about physically dominating your opponent and making him submit. And just when you get ready to stack the box against them, they will use play-action to attack deep with Terrance Williams, Dez Bryant and Jason Witten. If they can avoid key injuries, like any team, this offense will be hard to stop all season.

Fox: I think we probably won't know the answer until late November/early December, when the Cowboys and Eagles play twice in three weeks, beginning on Thanksgiving in Texas. Given the Cowboys' schedule between now and then -- Dallas gets the New York Giants twice, Washington Redskins, Arizona Cardinals and Jacksonville Jaguars -- they could go into that game on a 10-game winning streak. If nothing else, they should be in position to take the division from the Eagles, who went into the season as the prohibitive favorite.