IRVING, Texas -- On Sunday, ESPN and Pro Football Focus unveiled a project to determine how close each team not in Super Bowl XLIX is to playing in the Super Bowl.

The Dallas Cowboys were deemed to be the closest of the 30 teams not in the Super Bowl. PFF graded the Cowboys with four elite players, eight good players, 16 average players and just two bad players.

But close is a relative term. Thirteen of the 30 players rated by PFF are set to be either restricted or unrestricted free agents. Teams change. Opponents change. What is true today won’t be true in September when the season begins.

“I think more so now than ever before,” tight end Jason Witten said, “I think we have an identity in which how we play. And I think that’s something that you feel like you’re building and can build upon. Coach [Jason] Garrett did a great job of kind of enforcing that, kind of laying out that as a blueprint week in, week out since April of what’s going to allow us to have success. Having said that, you start over. No team's the same, and so you have to build that again. I think it was good for us to taste that. It was good for guys to get back there.

“But I don’t think that says next year just roll the ball out and we’re going to do it again. No, you’ve got to do it all over again. I do think we’re good at the right positions that will allow us to have a chance to be successful.”

The Cowboys should have the best offensive line in the NFL with Tyron Smith, Travis Frederick and Zack Martin leading the group. Tony Romo had his best season. Dez Bryant, who is set to be a free agent, is among the best wide receivers, as is Witten among the best tight ends.

But then there’s DeMarco Murray. Like Bryant, he is set to be a free agent but there is no guarantee he will be back. If they have to use the franchise tag, it will be on Bryant.

If Murray leaves, the dynamics of the offense are sure to change. Maybe Joseph Randle can replace Murray. Or maybe Adrian Peterson, in fact, ends up a Cowboy. Or Mark Ingram. Or maybe some rookie. Maybe doesn’t fit into an equation.

And this is where "close to the Super Bowl," talk is not necessarily realistic. Thirteen of the 30 Cowboys graded by PFF are free agents, either restricted or unrestricted.

Eight of those 13 players are on the defensive side of the ball, including the leading tackler (Rolando McClain), leading interceptor (Bruce Carter) and second-leading sacker (Henry Melton). Key contributors like Anthony Spencer, Justin Durant and Sterling Moore (restricted) could hit the market to some degree.

When Garrett’s five-year extension was announced shortly after the Cowboys' season ended, he mentioned the word "build" in his opening statement.

“I think teams make mistakes when they say, ‘OK, we’re one player away,’” Garrett said. “I just think you’re continuing to try and build a football team. If we do that, right guys, the right way, that’s what gives us our best chance.”

The quick fix in free agency is sometimes never quick or a fix because the cost is so prohibitive. The Cowboys signed Brandon Carr in 2012 to a five-year, $50 million deal but he has not played to that level and entering his fourth year with the team he is looking at a pay-cut-or-be-cut scenario.

There is also the element of luck. Was it lucky that Tony Romo spun away from J.J. Watt and found Terrance Williams for a touchdown in the overtime win against the Houston Texans? Was it good fortune that the Cowboys were matched up with the dreadful AFC South?

The Cowboys saw a bit of bad luck in the playoff loss to the Green Bay Packers when Bryant’s catch was overturned.

“Sometimes it’s the way the ball bounces,” Frederick said. “You’re on the sideline and you drop one and it might bounce out of bounds or it might bounce back in and the other team picks it up. There really is a bit of luck in there.”

Each year is a delicate balance of skill, luck, health and chemistry mixed in with a team’s ability.

The 2014 Cowboys were close to contending for the Super Bowl. That doesn’t mean the 2015 Cowboys will be close to competing for Super Bowl L.

“One of the things you learn early on in this game is if we brought back the exact same team, the exact same players, the exact same coaches and we got together on April 20 for the start of the offseason program, we have to start all over again,” Garrett said. “So I do believe that you get yourself to a point and the experiences that we’ve had up to this point are real ones and we can benefit from those experiences, actual game experiences, success and adversities and all that, so we start from that point but we have to get back to work.

“We have to put our socks back on and start from the ground floor and do it all over again. That’s an exciting thing.”