The chicken or the egg?

DeMarco Murray's sudden successful outburst which culminated in a 2014 NFL rushing title or the outright dominance of the Dallas Cowboys offensive line, comprised of former first-round picks, Tyron Smith, Travis Frederick and Zack Martin?

Which came first? Or, perhaps more accurately, which factor led to the other's high level of success? (Author's note: the possibility that it was a byproduct of two strong forces working together in harmony, creating an outcome that was, in fact, greater than the total sum of the parts, is boring and probably accurate so therefore we will ignore it)

That's for head coach Jason Garrett and the Cowboys to know - or think they know - and the rest of us to find out once the regular season rolls around.

Garrett, speaking at the NFL's owners meetings in Phoenix Monday, admitted that he was disappointed to see Murray, a player he said he had immense respect for, leave the team in free agency.

"DeMarco is a great football player and a great young man,'' Garrett said, per David Moore of The Dallas Morning News. "What he was able to do for our ballclub last year was phenomenal. He had a huge impact on the success that we had."

Garrett said that while he and Stephen and Jerry Jones had hoped to keep Murray a member of the Dallas franchise for the foreseeable future, the financial aspect of the situation kept that from becoming a reality.

"We wanted him to be a Cowboy not just for this coming year but for many years to come. But there is a business aspect. He had to do what he felt was right for him and his family, and we had to do what was right for organization," said Garrett.

"Unfortunately that didn't work out. Now we have to move on and make the next best decision for our team.''

The best decision for the Cowboys meant allowing Murray to walk away to the division rival Philadelphia Eagles and signing the oft-injured Darren McFadden as a boom-or-bust type replacement. There's also the looming 2015 NFL Draft and every possibility the Cowboys will wind up using a fairly high selection on a ballcarrier or two in what is considered a deep draft for running backs - perhaps Todd Gurley or Melvin Gordon?

Garrett, despite his disappointment at losing Murray, said that the team and the offense will continue to operate the same way it did last season en route to a postseason berth and Wild Card victory over the Detroit Lions.

"It was a good style of football for us to play. We will try to continue to do that.''

The combination of Murray's nimble-but-rugged running style and the Cowboys ferocious offensive line was nearly unstoppable at times last year. Losing a main component to what had become a well-oiled road-grating machine means the success they found on the ground - 508 total carries, 2,354 yards and 16 touchdowns - will be difficult to duplicate.

We'll find out pretty quickly once the 2015-16 season rolls around whether the Cowboys can keep playing that same type of power football and whether it was Murray that was the engine that kept the Dallas offense rolling or if he was simply the benefactor of a fearsome offensive line ready to turn another good running back into a great one.