Was firing Rob Ryan right move for Cowboys?

Jerry Jones promised changes but was it the right move to part ways with defensive coordinator Rob Ryan?

Jerry Jones promised changes last week and the Cowboys owner delivered Tuesday by firing defensive coordinator Rob Ryan.

Was it the right change?

Looking at all the facts and numbers — and knowing the Cowboys' biggest weaknesses — the firing of Ryan smells like a case of merely making a change for change's sake. That's usually the worst reason to make a franchise-altering change.

Jones had to do something after a second consecutive 8-8 season. The owner obviously felt embarrassed losing a chance at the playoffs in the final week of the season to a division rival (Washington) — for the second year in a row.

But with all the Cowboys' struggles, it's hard to make an argument that the way Ryan ran the defense was the biggest reason the team failed to make the postseason.

With any other franchise that posted just one playoff victory in the last 16 seasons, the No. 1 head on the chopping block would be the general manager ... but that's not going to happen. Jones has elected himself GM for life, and he has the only vote.

Next, the head coach would be let go. That's not going to happen, either, as Jones has repeatedly pledged his faith in Jason Garrett. Canning Garrett now would mean Jones admitting a big mistake, and he's as loathe to do that as lowering ticket prices.

Third on the list of major changes would be dumping the turnover-prone starting quarterback. That wasn't going to happen thanks to salary-cap concerns, as well as the sheer difficulty in finding a suitable a replacement.

So it's down to the coordinator position. Bill Callahan has the title of offensive coordinator, but in reality the offense is Garrett's baby.

That left Ryan as the next in line to be the sacrificial lamb. His defenses haven't been great, and at times his creativity put the defense in bad spots. But he's only been here two seasons, which were greatly affected by issues beyond Ryan's control.

In Season One, the installation of his system was scuttled by the labor dispute. In Season Two, his defense was gutted by injuries.

It's a wonder the Cowboys didn't finish worse than 19th in the league in total defense with a team that lost both of its starting inside linebackers — including coach-on-the-field Sean Lee, its top two nose tackles, a starting safety and a starting defensive tackle.

By the end of the season, the defense's biggest star, DeMarcus Ware, was a one-armed shell of his former self.

It wasn't the defense that lost the finale against Washington, although Redskins running back Alfred Morris rushed for 200 yards straight up the Cowboys' wounded middle. The defense allowed 21 points in the 28-18 loss. It was quarterback Tony Romo who threw the dagger interception with three minutes left that the Redskins converted into a touchdown.

Romo threw two other interceptions in that game that could be blamed on miscommunication with receivers. That's right, in Week 17 the quarterback and receivers were still not of one mind, and the offense continually had trouble getting plays off in time.

If you want to poke a finger at the defense, go back to the week before when Drew Brees passed for 446 yards in a 34-31 overtime win for the Saints. Ryan's defense allowed 562 yards without recording a sack.

But if you're going to measure defensive coordinators on how their squads do against Brees, there's going to be a lot of guys drawing unemployment. Given that Ryan was playing a bunch of guys signed off the street, the so-called "Name Tag" defense, a bad day against the Saints could, should be forgiven.

Jones, however, is not in a forgiving mood. He is increasingly painting himself in a corner with his personnel decisions and someone has to take the fall.

By far, the Cowboys' biggest weakness in 2012 was a below-average offensive line that could neither protect Romo nor get any kind of push for DeMarco Murray and Felix Jones.

It was Jones who signed sub-par free agents Mackenzy Bernadeau and Nate Livings to serve as the starting guards. Jones also gave right tackle Doug Free a big contract and, by the end of the season, Free was alternating with Jermey Parnell.

The Cowboys were also forced to acquire Ryan Cook in a last-minute trade to serve as the starting center this season.

Knowing full well the holes in the offensive line, where 2011 first-round pick Tyron Smith is the only reliable starter, Jones traded up in last year's draft to get Morris Claiborne. Cornerback was also an area of need last offseason, but the Cowboys had already signed high-dollar free agent Brandon Carr, and there was more depth at corner than in the offensive line.

Not that Jones hasn't ignored the offensive side in his sweeping changes. He fired running backs coach Skip Peete on Monday. Obviously, the running backs were not being taught how to run through holes that didn't exist.

Jones promised a week ago that it would get "very uncomfortable" at the Valley Ranch practice facility in the coming weeks and months. Maybe there are more moves to come, but if Ryan is merely the scapegoat for larger ills, there's reason to be uncomfortable about the direction of the franchise. Very uncomfortable.

Follow Keith Whitmire on Twitter: @Keith_Whitmire