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Lamar Miller enjoyed something of a breakout season last year.

The now 24-year-old running back finished the season with 1,099 rushing yards and eight touchdowns. It was his first year ever eclipsing 1,000 yards after totalling just 959 rushing yards over his first two seasons in the league.

Miller wasn't supposed to crack 1,000 yards last season. The Miami Dolphins coaching staff and front office did everything they could to prevent it.

Adding Knowshon Moreno in the offseason was supposed to relegate Miller to a two-back system, likely even pushing him as far as the minority holder of the touches at the position. Moreno was lost to injury during the season after featuring in just three games.

Outside of direct attempts to replace him, the Dolphins also failed to address the interior of their offensive line. Branden Albert and JuWuan James had arrived to improve pass protection on the edges, but it was Samson Satele and Daryn Colledge amongst others playing alongside Mike Pouncey on the interior.

Even with Moreno sidelined, the Dolphins were reluctant to rely too heavily on Miller.

The Dolphins ran the ball with a running back on 330 occasions last season. Miller got the majority share but finished the season with just 216 carries and 38 receptions. He averaged 13.5 rushes per game, and the Dolphins were consistently reluctant to keep feeding him the ball after a number of productive runs.

Joe Philbin and Bill Lazor were clearly wary of their smaller running back wearing down over the season and didn't trust his durability. As such, Miller spent the offseaosn adding weight, 15 pounds to be precise.

Even though Philbin and Lazor clearly were reluctant to feed Miller more carries, they gradually gave in as last season progressed. Over his final three games of the year, Miller had 17, 24 and 19 touches. When opportunities arose to add running backs in the offseason, the Dolphins weren't aggressive.

They selected Jay Ajayi in the latter rounds of the draft, a talented running back who has major knee issues that could end his career at any moment.

With Damien Williams on the roster as an impressive third-down option, Miller appears to be the clear favorite to carry the load in 2015. While it's tough to trust Philbin based on past actions, he did say ahead of this season that the Dolphins will be looking to rely on Miller more (via James Walker of ESPN.com):

I would tell you, if he’s cranking and he got it 24 times a game and he’s healthy and he’s fast and he’s explosive, it doesn’t bother me one bit. ... I kind of look at Lamar a little bit like Ryan Tannehill in the sense that you rush for 250 yards as a rookie, 700 in his second year and almost 1,100 last year. So you see progress, and you see development.

Offensive coordinator Bill Lazor is the orchestrator of the Dolphins offense. He implemented a system that shares many traits with Chip Kelly's in Philadelphia. Lazor was Kelly's quarterbacks coach before he became the Dolphins offensive coordinator last year.

If Lazor wants to push his offense further into the Kelly mold, he will need to run the ball more than he did last season. Furthermore, Lazor may be set up to call more runs with a much-improved defense.

The Dolphins ran the ball 330 total times with their backs last year. LeSean McCoy, during a supposedly down season, ran the ball 312 times on his own in 2014. Add in the other running backs, and the Eagles had 415 rushes from running backs in 16 regular season games.

Although Miller should expect more carries this season, it's unlikely that he cracks the 300 mark. Even if he can get close to 275 while maintaining his average per carry from last season, he will have a huge year. Miller averaged 5.1 yards per carry last season, so 275 carries would lead to 1,400 yards.

Extrapolating an average per carry onto a greater sample size is always a dangerous endeavor. Miller isn't going from a complementary role to that of a bell-cow back though. He's adding fewer carries than he's already had.

Most importantly, his skill set suggests that he can sustain his success, and he isn't simply reliant on big plays that bloat his average.

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Miller is a perfect fit in the Dolphins offense because he has the speed, quickness and vision to exploit the space it naturally creates. Therefore, the risk of losing speed after adding weight in the offseason was more significant for him than is typically.

Fortunately for all involved, it appears that Miller still has his burst, despite his weight gain.

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This play comes from the first preseason game of the year, against the Chicago Bears. Chicago's defensive front is pushed toward the far sideline as the Dolphins run their typical zone-blocking scheme up front. When Miller takes the ball, he has a tight end pulling across the formation behind the line of scrimmage.

It's unclear if this is a designed cutback run, but either way, Miller follows his tight end to space.

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After turning toward the sideline, Miller is faced with two defenders and just one blocker. His blocker accounts for the defender furthest to the outside, leaving an unblocked defender in the inside running lane. Miller has to make an immediate decision and show off enough speed to get outside.

His quickness and acceleration to get to the outside is impressive.

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Once he gets to the edge, Miller is able to show off his speed in space. He quickly advances downfield, surpassing the first down marker and heading toward the sideline. He never had a real opportunity to extend this play to the end zone because of the deepest defender's angle.

Miller still pushed the defender's range for a 27-yard gain.

Getting Miller to either edge is always going to be a priority for the Dolphins offense. With more athletes lining up on the line of scrimmage this season, they should be more effective in doing that. Against the Atlanta Falcons in the third week of the preseason, Miller got a clean route to the outside.

He even had blockers out in front.

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That play was negated for a penalty, but it was a good example of the type of run the Dolphins can mix into their running game to stretch the defense horizontally. It's difficult to match up to Miami's running game because it doesn't just attack you in one way or one area.

Miller is a key to that because he can work between the tackles in this system.

Even when the Dolphins run between the tackles, they are often running to space. That is because they make use of Ryan Tannehill's athleticism from shotgun alignments to hold backside edge defenders instead of blocking them.

Given this added advantage of working with an extra blocker, Miller can consistently set up his blocks and locate the correct running lane.

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During Week 17 of last season, Miller had his longest run of the year. It was a 97-yard gain against the New York Jets. Miller initially lined up in the backfield alongside Ryan Tannehill. He had six blockers in position in front of him, with only five defenders lined up between the tackles and one tight to the left tackle.

Out of picture in the top image is another linebacker to the left. That linebacker has been stretched wide by a slot receiver to that side.

Just before the ball was snapped, Miller had swapped sides to line up to Tannehill's right. This was so the quarterback could read the left outside linebacker during his handoff. Tannehill's eyes and posture forced the linebacker to stay wide when the ball was snapped.

This allowed the six blockers to ignore the left edge defender and crash down inside on the five defenders who initially lined up between the offensive tackles.

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By the design of the play, Miller's first steps direct him towards the A-Gap between his center and right guard. He is quick to turn back towards the cutback lane that is wide open, though. Miller had to make those initial first steps to hold the linebackers inside.

His footwork and vision were perfect on this play, giving Miller an opportunity to quickly attack the space on the second level of the defense.

Once in space, Miller was able to outrun the angle of the safety and turn upfield to run down the seam. He sustained his speed for 55-60 yards, slowing down enough to let a cornerback recover just as he crossed the goal line.

Recognizing when to cut back gives Miller lots of opportunities for big plays, but his willingness to press holes in front of him is just as valuable.

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On this play against the Buffalo Bills, the offensive line isn't going to zone-block. Instead, the Dolphins trap the right defensive tackle downfield with their left guard while pulling the center in behind him. Meanwhile, the right guard advances to the second level to push a linebacker out of the play.

Miller takes the ball from Tannehill directed towards the exact spot where the left guard was.

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Although it's subtle, Miller makes a cut behind the line of scrimmage that helps to set up his blocking up front. He initially hesitates while drifting towards his left tackle before planting his foot to press back inside.

By the time he is crossing the line of scrimmage, the second-level linebacker has been completely pushed out of the play.

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Miller didn't have to touch a defender before he reached the line of scrimmage, but after gaining four yards he was met by a safety in space. Miller runs hard through the safety and finishes the play moving forward for an extra two yards.

This is the kind of play that should be helped the most by Miller's weight gain. He will be able to run through bigger tacklers, while also breaking arm tackles and pushing the pile through tighter running lanes.

Even last season, before his weight gain, Miller could be an effective goal-line back in this system. Although Ajayi figures to be a more physical player at the point of contact because of his size, his running style doesn't always boast brashness.

He is too quick to break outside and shuffle his feet instead of putting his head down.

Miller's aggressiveness should allow him to maximize his scoring potential. Eight touchdowns rushing is already a significant number, but it's a number that Miller can build on. It's especially impressive when the running back is also a receiving threat.

Although Miller is a threat as a receiver, the presence of Damien Williams and the additions of so many receiving options around Tannehill will likely hurt his production there.

The Dolphins offense is set up to be one of the best if not the best unit in the NFL next season. Their offseason additions have been well thought through and add a level of quality that wasn't previously there. The expected improvement of Tannehill as an individual is already being widely talked about.

Because he's a carryover player and not the quarterback, Miller is being overlooked somewhat. Yet, now that he is entering his prime while playing in a perfect scheme fit, Miller should be a key player for the Dolphins and one of the better running backs in the NFL.