Dallas Cowboys running back Ezekiel Elliott led the NFL in rushing yards last season, finishing with 1,434 yards and six touchdowns in a season where the team went 10-6 and made it to the divisional round of the playoffs.

Based on that, the running game should be the least of the Cowboys worries. However, dive a little deeper and it's easy to see that the Dallas running game left a lot of meat on the bone last year.

The best way to showcase this is through success rate in the running game. Success rate is a simple metric that measures exactly what the name indicates -- how often a player is "successful" with the ball in his hands. A play is deemed successful when it gains at least 40% of the yards-to-go on first down, 60% on second down and 100% on third or fourth down. Success rate is a more valuable tool than traditional stats such as yards per carry because it adds context (down and distance) to any given play.

Despite possessing the NFL rushing leader, the Cowboys finished in the middle of the pack (15th) in terms of rushing success rate (47%) per Sharp Football Stats. On top of that, the NFL rushing leader (Elliott) finished 20th among RBs with at least 100 rushing attempts in rushing success rate (49%), per Sharp Football Stats.

For comparison's sake, the three teams who led the NFL in rushing success rate last season were the Los Angeles Rams (59%), Kansas City Chiefs (55%) and New Orleans Saints (55%). That means the top three teams in rushing success rate all made their conference championship games in the playoffs. Moreover, the Super Bowl champion Patriots weren't far behind, finishing eighth in rushing success rate (51%).

For a team whose identity is to run the ball, being successful on less than half of the team's runs should be unacceptable. Yet there's been little talk this offseason about how the Cowboys can improve their rushing attack. And while the Cowboys should look to improve the passing game, they would be wise to not ignore the running game in the process.

With that in mind, there will be no disregard of the running game today, as we take a deep dive into how the Cowboys can improve (and become more efficient with) their running game next season.

Health of the offensive line

Dallas Cowboys tackle Brandon Knight (center) runs through drills with his other offensive linemen during the Cowboys rookie minicamp practices at The Star in Frisco, Texas on Friday, May 10, 2019.(Shaban Athuman/Staff Photographer) (Shaban Athuman / Staff Photographer)

Let's get the simple stuff out of the way first. The Cowboys dealt with their fair share of injuries up front, finishing 24th in adjusted games lost -- which measures just how injured each team and unit was compared to the rest of the NFL -- on the offensive line, per Football Outsiders.

All-Pro center Travis Frederick missed the entire season. All-Pro left tackle Tyron Smith missed two games because of injuries. Rookie left guard Connor Williams missed games because of a knee injury and his replacement Xavier Su'a-Filo also dealt with an ankle injury that forced him to miss some time. While La'el Collins didn't miss much time, he dealt with his own assortment of ailments, one of which was a torn rotator cuff that had to be surgically repaired this offseason.

The injury bug bit the Cowboys offensive line hard last season. That has to account for some of Dallas' inefficient running game last season. The myriad of injuries up front prevented the Cowboys from building continuity on the offensive line, which is key to being consistently effective up front.

Even though it's almost impossible to get through a season unscathed up front -- unless you're the Rams, who have led the league in adjusted games lost on the offensive line each of the past two seasons with less than one game missed by the OL each season -- more favorable injury luck this season should, in theory, lead to a more efficient running game for the Cowboys.

Better continuity on the offensive line should enable the running game to have better timing and consistency. When an offensive line stays intact throughout the season, the running backs behind it get more comfortable with the reads and timing of each play. The running backs start to identify the trends of each offensive lineman, which will better inform their decision-making on a play-by-play basis.

For example: if Elliott knows that Connor Williams is a little slow in climbing to the second level after double-teaming the defensive tackle on a combination block, he may wait an extra half-second before hitting the hole so that Williams has the time to cut-off the linebacker and create a large running lane.

Moreover, if Elliott knows that Zack Martin is little quicker to climb to the second level, he may hit the hole a little bit faster, so that he can best take advantage of the crease created by Martin.

Those types of things take time to develop, which is why health and continuity are key for the Cowboys' run game this season.

RELATED: Travis Frederick's path back to football, the Cowboys -- A stubbed toe, shoulder surgery and his next big test

Manipulate boxes better

Dallas Cowboys running back Ezekiel Elliott (21) picks up the first down as the Cowboys went for it on 4th and 1 against the Los Angeles Rams in the first quarter of their NFC Divisional Playoff game at Los Angeles Memorial Coliseum in Los Angeles, Saturday, January 12, 2019. (Tom Fox/The Dallas Morning News) (Tom Fox / Staff Photographer)

One of the areas where coaching and play calling held the Cowboys back most last season was in the run game. The Cowboys were much too predictable with their play calls and uniform with their formations, which allowed for defenses to load the box and slow down Dallas' running game.

During the season, we lamented about the Cowboys' propensity to run from heavy and condensed formations in short-yardage situations, as it enabled opposing defenses to load up the box and stop the Cowboys rushing attack far too often.

Through Josh Hermsmeyer's research at FiveThirtyEight, we know that NFL offenses average more yards per carry with fewer defenders in the box. Combine this with the fact that Elliott was one of only two running backs (the other was Derrick Henry) with at least 1,000 yards rushing who also saw at least eight defenders in the box 23% or more of their attempts.

On its face, it seems obvious as to why Elliott would face such a high number of eight defenders in the box, as the Cowboys are a run-first team with the best running back in football -- of course teams are going to load up the box to stop him.

Nevertheless, further investigation reveals that may not be the case. The Seattle Seahawks, who were the most run-heavy team in the NFL, ran the ball against seven-or-less defenders in the box with the fifth-highest frequency, per Sports Info Solutions, whereas the Cowboys finished 12th.

Furthermore, Elliott alone wasn't the reason for the high percentage of eight-plus defenders in the box, as Todd Gurley, who is largely viewed in the same tier of RB as Elliott, faced eight-plus defenders in the box on just 8.2% of his rushing attempts -- Elliott saw eight-plus defenders in the box on 24.67% of his carries, per Next Gen Stats.

The best way for an offense to manipulate a defense into committing less defenders to the box is by spreading out the formation. The Cowboys should stop using heavy personnel and condensed formations en lieu of a more spacious formation that take advantage of the space available on the field.

Less zone in the red zone

Dallas Cowboys running back Ezekiel Elliott (21) runs to the end zone for a touchdown after a handoff from quarterback Dak Prescott (4) during the fourth quarter of an NFL playoff game between the Dallas Cowboys and the Seattle Seahawks on Saturday, January 5, 2019 at AT&T Stadium in Arlington, Texas. (Ashley Landis/The Dallas Morning News) (Ashley Landis / Staff Photographer)

One of the most concerning facets of the Cowboys rushing attack last season was its ineffectiveness in the red zone. The Cowboys had 54 red zone rushes in 2018 and finished with just eight touchdowns and a 44% success rate, which ranks 23rd in the NFL, per Sharp Football Stats.

The Cowboys were even worse inside the 10-yard line, where they finished tied for 26th in the NFL with a 43% success rate on the ground. Making matters worse, the team's success rate fell to 41% (28th) inside the five-yard line.

In theory, the Cowboys were built to thrive in this area, which is why they've invested so many resources in becoming a dominant run team. Frederick's absence likely played a part in this, but it's still not an adequate excuse when the team has two other All-Pro offensive linemen and the best running back in the NFL.

One way the Cowboys can be more efficient and effective with their red zone rushing attack is by utilizing more power/gap schemes and less zone concepts near the goal line.

FiveThirtyEight's Josh Hermsmeyer did the research and concluded that NFL teams were more effective with power/gap schemes near the goal line than zone concepts. Combine this with the fact that the Cowboys ran inside or outside zone on 56% of their carriers, per Pro Football Focus, and it begins to paint the picture as to why the Cowboys may have struggled running the ball in the red zone.

In theory, it makes sense as to why the gap style runs are more effective than zone concepts near the goal line, as vertical displacement from blocks is more important than horizontally stretching the defense.

Near the goal line where space is condensed and defenders attack their run fits quicker, indecision, or patience, by the ball carrier gives the defense too much time to react and make a play.

On zone runs, running backs are taught to make their decision on where to go by their third step. This is fine under the constraints of a typical run play where defenders are playing from more depth and must adhere to their run/pass responsibilities more strictly. However, near the goal line, waiting until the running back's third step to determine his path is simply too long.

A better idea would be to predetermine the running back's gap, which is the case on most power/gap schemes, as it enables the play to hit quicker, giving the defense less time to penetrate and make a stop.

Whereas on zone runs defenders have an extra second to penetrate as the running back determines his path, on gap runs, the defender must get immediate penetration off the snap to blow up the play. Furthermore, it is easier for an offensive lineman to prevent penetration where he's looking to displace defenders vertically rather than horizontally -- as horizontal movement often naturally widens the space between offensive linemen, which can be taken advantage of by the defense.

This doesn't mean that Dallas should do away with zone runs near the goal line as it's important to not be predictable in key situations. Furthermore, certain teams may be deficient at defending zone runs in the red zone, which would be a situation where Dallas would be wise to take advantage.

Yet, it does mean that, in large part, the Cowboys should run a heavier dose of power/gap schemes in the red zone.

After using zone concepts on 56% of their red zone runs in 2018, the Cowboys would be wise run power/gap schemes on over 50% of their red zone runs in 2019.

Use Dak's legs more

Dallas Cowboys quarterback Dak Prescott (4) runs for a would-be fourth quarter touchdown in their NFC Wild Card win over the Seattle Seahawks at AT&T Stadium in Arlington, Texas, Saturday, January 5, 2019. Dak came up short but ran in the touchdown a couple plays later. The Cowboys won, 24-22. (Tom Fox/The Dallas Morning News) (Tom Fox / Staff Photographer)

Dak Prescott's legs may be the single most underutilized concept in the entire Cowboys playbook. On 83 carries (53 were designed runs), including scrambles, Prescott had a 51% success rate, which a full four percentage points higher than the team as a whole and two percentage points higher than Elliott.

Furthermore, when you get into the red zone, Prescott becomes even more venomous, accumulating eight touchdowns and a 74% success rate (third among all players with at least 10 red zone carries) on runs inside the red zone.

Inside zone read ends up as a 17-yard TD run for #Cowboys QB Dak Prescott pic.twitter.com/FchPvwBEga — John Owning (@JohnOwning) October 14, 2018

The Cowboys were extremely effective using Prescott's legs as a part of packaged plays such as run-pass options (RPOs) and zone reads. These plays are great because they create an extra blocker by "reading" an unblocked defender.

More QB draws, please. Obviously not ideal to put your QB in harm's way like this, but this offense needs to do everything it can to move the ball. pic.twitter.com/uZg9Ag7uIF — John Owning (@JohnOwning) October 8, 2018

On top of using Prescott's legs on RPOs and zone reads, the Cowboys would be wise to utilize him more on QB draws, as it takes advantage of aggressive defensive lines and gets Prescott into the open field, where his vision and powerful running style enable him to find a great deal of success.

Now, the Cowboys have to be careful with the frequency of designed runs, as they don't want to risk Prescott's health too much. However, they can certainly do better than just three per game (53 designed runs over 18 games, which includes playoffs). For comparison's sake, Carolina's Cam Newton averaged just over five designed runs per game while Baltimore's Lamar Jackson nearly eight designed runs per game.

Giving Prescott the ball on designed runs five or six times per game instead of two or three could have a tangible positive impact, especially in the red zone, on the entire Cowboys running game.

Final thoughts

Overall, the Cowboys would be wise to tinker with their running game to become more efficient and effective in 2019.

If the Cowboys are healthier up front, manipulate defenses to see fewer eight-man boxes, run less zone in the red zone and use Prescott's legs more, their rushing attack could make noticeable improvements next season, making life easier on the defense and Prescott's arm in the meantime.

Enjoy this post?

More film studies: How Cowboys' Zack Martin leverages one specific technique to separate himself as NFL's best guard

Twitter: @JohnOwning