Year-by-year improvement is necessary to build a sustained contender in the NFL. The Dallas Cowboys have failed to build a sustained contender since the 90s, only making the playoffs in back-to-back years once (2006-07).

This year, Jason Garrett and Co. are looking to build off a 9-7 season where the Cowboys were forced to watch the playoffs from their couches, just like the rest of us. Dallas is going to need to improve in multiple areas to have the privilege of playing football into late January.

The idea of improving may bewilder many of the Cowboys faithful. Jason Witten, Dez Bryant

Dan Bailey are gone. Many are worried how that will affect Dallas' record.

It's "not about the X's and O's, it's about the Jimmy's and the Joe's" after all right?

Sort of. It does take some modicum of talent to be successful in the NFL. However, proper coaching and strategy can mask some talent deficiencies. Look at the Super Bowl champion Philadelphia Eagles.

The Eagles lost their starting quarterback who was on a path toward NFL MVP, their former All-Pro starting left tackle and their best linebacker, yet they were still able to bring home a Lombardi trophy. An innovative game plan, effective play-calling

fantastic situational awareness made up for the perceived loss of talent.

The Cowboys coaching staff will need to do their best to mitigate the personnel losses. The Cowboys coaching staff must raise the level of play from the team by developing the individual players and constructing weekly game plans that best play to the team's strengths - much easier said than done.

Even with the departures, it's not like the Cowboys are devoid of talent, either. Ezekiel Elliott is still among the best running backs in the NFL, the offensive line is still potentially dominant (though it does get a little more difficult with All-Pro center Travis Frederick out to start the season), and the defense looks much improved from a year ago.

The Cowboys can make the playoffs and threaten to make a deep run this season. But the team will need to improve in a few key areas to achieve that reality.

Mitigating the loss of an All-Pro offensive lineman

Last season, the Cowboys struggled when another All-Pro offensive lineman, left tackle Tyron Smith, missed two games toward the end of the season. The coaching staff failed to craft a game plan that properly protected Chaz Green and, eventually, Byron Bell, which caused the offense to tailspin:

Without Smith, the Cowboys' run and pass success rates, defined as a player gaining 40 percent of needed yards on first down, 60 percent of needed yards on second down, or 100 percent of needed yards on third or fourth down, dwindled.

While the Cowboys' explosive run percentage - the percentage of runs that went over 10 yards - improved, the team's explosive pass percentage - the percentage of passes that went over 15 yards - shrunk. And Dallas turned the ball over more often and was sacked almost three times more frequently.

Jason Garrett and the Cowboys coaching staff were too stubborn with their game plans and failed to give Green and Bell the help they needed to survive on the edge. The Cowboys went 0-2 without Smith as a result.

This year, the Cowboys must play without an All-Pro in Travis Frederick, who will miss an undetermined amount of time after being diagnosed with the autoimmune disorder Guillain-Barre Syndrome.

Frederick's replacement will be veteran center Joe Looney, who performed well throughout the preseason. The coaching staff will need to remain flexible in Frederick's absence to make any necessary adjustments on the fly.

If the Cowboys hope to make the playoffs, they need to better adapt to the loss of Frederick than they did with Smith a year ago.

Third-down defense

In 2017, the Cowboys' defense was putrid on third downs, allowing a 42.86 third-down conversion percentage (fourth-worst in the NFL), per Team Rankings. The defense was especially bad in third-and-short (one yard or less to go for a first down) and third-and-medium (between six and two yards to go for a first down) situations, per SBNation's Bill Connolly.

The biggest reason the Cowboys struggled on third-and-short and third-and-medium situations was the interior defensive line's poor play, especially when David Irving missed four games each to suspension and then injury.

In fact, offenses converted 100 percent of their chances when they ran the ball on third-and-short situations against Dallas, averaging 4.1 yards per

,

according to Sharp Football Stats

. In third-and-medium situations, the Cowboys defense allowed opponents to convert first downs 58.8 percent of the time, allowing six yards per

in the process.

This play is a great example of the Cowboys' issues on third-and-short and third-and-medium situations (Lewis Neal is the bottom arrow and Maliek Collins is the top arrow):

On this play, the Giants are in a third-and-1 situation in the red zone. They are in a

set using 11 personnel (one running back, one tight end, three wide receivers) while the Cowboys are in their nickel defense (four defensive linemen, two linebackers, five defensive backs). After the ball is snapped, Neal is stopped in his tracks and driven back at the point of attack by the left guard while Collins gets blown off the line of scrimmage by the center and right guard, giving New York an easy third-down conversion.

The addition of Antwaun Woods should help the Cowboys in this area, as the powerfully built 6-foot-1 and 312-pound defensive end

in holding his ground against the run. Tyrone Crawford playing more defensive tackle should help as well, as he's always been effective against the run regardless of position.

On the other side of the coin, Dallas needs Collins to hold his ground and defend the run better and more consistently in 2018. Collins frequently got displaced from his gap in 2017, leaving gaping running lanes and making life difficult on the linebackers.

If the Cowboys can get better play from their defensive tackles against the run, they should fare better on third down.

Big plays in the passing game

The Cowboys offense struggled in 2017, and lacking an explosive passing game was one of the biggest reasons why.

After completing 36 explosive passes (passes that gained more than 15 yards) in 2016 (15th in the NFL), Dak Prescott and the Cowboys offense completed just 20 in 2017 (31st in the NFL), per Sharp Football Stats. The drop in explosive pass plays is partly due to Prescott's diminished accuracy in 2017.

In 2016, Prescott was well above average on passes that traveled 10-or-more yards in the air, per AirYards.com. In 2017, however, Prescott's accuracy dipped to below average on passes that went 10-or-more yards in the air.

One of the main reason for Prescott's inaccuracy on potentially explosive pass plays is his footwork. This play is a good example:

Here, Prescott looks to complete a deep pass to Terrance Williams, who was able to get open on a "

" route (receiver sells a slant before streaking down the field on a go route). However, Prescott overthrows Williams and is unable to convert on the potentially explosive pass. Let's take a closer look at Prescott's footwork:

The key problem in Prescott's footwork can be identified by his lead foot. Notice how it slightly rotates to Prescott's left during the throw. Prescott is not properly transferring his weight from his back foot to his front foot, which means he's not generating enough power from his hips. He's relying on just his arm to generate velocity on the throw, which leads to inconsistent throwing motions and general inaccuracy as a passer.

When a quarterback is properly transferring his weight and generating power through his hips, his front foot should remain stationary through the quarterback's follow-through because it is absorbing the impact of the weight transfer.

If Prescott can become more consistent with his footwork, he will improve his velocity and accuracy on passes, meaning he will be able to convert more often on explosive play opportunities in the passing game.

John Owning writes about NFL player evaluation for SportsDayDFW.com. Follow him on Twitter at @JohnOwning.