If you drafted a running back early in your 2015 fantasy football draft, you more than likely weren't pleased with your return on investment. The position was an absolute wasteland, especially at the top end.

As our own JJ Zachariason pointed out, Adrian Peterson was the only running back among the top-10 preseason ranked backs to finish in the top 10.

Lamar Miller was one of the few running backs to justify his early draft position. According to MyFantasyLeague.com, Miller was taken as the ninth running back on average last season, but he finished the year as the fifth-highest scorer in points per reception (PPR) formats. Miller was able to put up those numbers in spite of the ineptitude of Miami's offense.

This offseason, Houston gave Miller more guaranteed money than any other free agent running back. After he piled up 236 total yards and 2 touchdowns against the Texans last season, it should come as no surprise that they were interested in Miller's services.

Despite finishing as the fifth-best running back and moving to a team that emphasizes running the ball, Miller comes into 2016 ranked as the eighth running back according to ESPN's Fantasy Football Rankings Summit. To be fair, two of the running backs ranked ahead of Miller (Le'Veon Bell and Ezekiel Elliot) weren't able to challenge Miller's top-five status last year, while neither Todd Gurley or David Johnson were starters for the full season.

Still, the move from Miami to Houston is a significant one for Miller's value.

Lamar Miller: The Workhorse

For whatever reason, Miami was insistent throughout Miller's career that he was unable to handle a heavy workload. In his four-year career with the Dolphins, Miller only averaged 10.6 carries per game. Even in his top-five fantasy season last year, Miller was only handed the rock 12.1 times per game. He logged single-digit carries in six games, which is simply absurd for a running back with his talent.

While Miller may be slightly undersized for the position at 5'10", his 225-pound frame is far from that of more slight running backs like Devonta Freeman (5'9", 209 pounds), Giovani Bernard (5'9", 208 pounds) and Duke Johnson (5'9", 210 pounds).

In the few games he was given close to a normal workload, Miller was very effective. Check out his splits over the past three years when he has received at least 14 carries:

Despite the obvious improvement in volume-based numbers, Miller also averaged a highly impressive 5.15 yards per carry in the 20 games in which he was given at least 14 carries. He showed no signs of wearing down when given a heavy workload, which is encouraging as he heads to Houston's run-heavy scheme.

The O'Brien Factor

Since head coach Bill O'Brien took over for Houston two seasons ago, the Texans have been one of the most run-heavy teams in the NFL. In their first season under O'Brien, the Texans ran the ball 551 times, which was the most in the league. They followed that up with 472 carries last season, which still ranked fifth. Over the past two seasons, Houston had a combined 1,023 carries, compared to Miami's 743.

The Dolphins ranked dead last in rushing attempts last year.

The table below clearly shows the difference between O'Brien's system and the offense Miller played in under Joe Philbin and Dan Campbell.

As JJ Zachariason previously discussed, the Texans actually posted a 1.08 drop back to rush ratio from Weeks 8-16 last season. After shoring up their mostly horrible defense to start the year, Houston resorted back to their run-heavy ways from 2014, during which which they actually ran the ball more times than they dropped back to pass.

While Miami only allowed Miller to carry the rock 14 times in 14 games over the past two seasons, O'Brien allowed Houston's running backs to handle that many carries 26 times during that span. That's even more encouraging for Miller's outlook when you consider that O'Brien rarely had a runner of Miller's caliber during that time -- instead having to make due with an oft-injured Arian Foster and the likes of Alfred Blue, Jonathan Grimes, and Chris Polk.

When Foster has been healthy over the past four seasons, Houston has shown commitment to him as a workhorse -- giving him an average of 24.9 touches in games he started. During that span, Foster reached the 14-carry mark in 33 of 34 games.

O'Brien's commitment to the run with the Texans should come as no surprise after his two years as the head coach at Penn State. His teams ran the ball more frequently than they passed in both 2012 and 2013 and posted a combined pass to run ratio of 0.88.

Lamar Miller's Receiving Ability

Assuming he stays healthy, Miller is a safe bet to post a career high in rushing attempts next season. His value is not limited to what he can do on the ground though, which he showed last season. In 2015, Miller caught 47 passes for 397 yards and 2 touchdowns -- all career highs. He was one of the most effective receiving backs in the league according to our Net Expected Points (NEP) metric. Check out more on NEP in our glossary.

Miller posted a 22.1 Reception NEP, which was the 15th-highest among running backs and the 4th-highest among running backs with at least 150 carries.

One cause for concern is that his Reception Success Rate (the percentage of catches that led to NEP gains) of 51.06% ranked last among 23 backs with at least 50 targets last season. He's got some big-play upside as a receiver, but consistent gains though the air weren't his forte last season.

Scoring Opportunities

Another thing that has allowed Miller to remain fantasy relevant despite mind-boggling low volume is his ability to find the end zone. Miller posted eight rushing touchdowns in back-to-back seasons for Miami, thanks in large part to his efficiency in the red zone.

Oh, it helps when you can do this, too.

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Last season, Miller led all qualified running backs (at least 20 red zone carries) in red zone efficiency, converting 30 percent of his carries for touchdowns.

Once again, the move from Miami to Houston should help him to capitalize on his strengths. Last season, Houston ran the ball 48 times in the red zone, as opposed to Miami's 35 red zone rushing attempts.

Offensive Line Improvement

In addition to giving their running backs more volume than Miami, Houston offers an improved offensive line to run behind. Pro Football Focus ranked Miami's offensive line as the second-worst overall offensive line and the worst run blocking line in the league in 2015. Houston's offensive line had some struggles of their own, but they ranked 18th overall and 24th in run blocking last season. Football Outsiders painted a similar picture, ranking Miami 28th in run blocking, while giving Houston credit for the 18th-best run blocking line in 2015.

Houston made apparent efforts to shore up any holes they had up front this offseason, spending a combined $34 million on Jeff Allen and Tony Bergstrom, both of whom have starting experience. They also used their second-round pick on center Nick Martin from Notre Dame.

It's clear that Houston has put an emphasis on getting the pieces in place to protect their two big-money free agents from this summer: Miller and quarterback Brock Osweiler. Osweiler is far from a sure bet for production, but he did post a higher Passing NEP per drop back (0.08) than Miller's 2015 quarterback, Ryan Tannehill (0.05).

Houston has done all they can to put him in a position to succeed, and their improved offensive line is highly encouraging for Houston's offense -- specifically Lamar Miller -- in 2016.

Conclusion

Miller finished as a top-five fantasy running back in 2015 despite being on possibly the least fantasy-point-conducive team in the league for a running back. Seemingly every fantasy relevant aspect has improved for him heading into 2016, yet he is likely to be drafted in the mid-to-late second round of most leagues.

Thankfully, the days of handling Miller with kid gloves are likely a thing of the past. Based on Houston's past running back usage, it wouldn't be a surprise to see Miller near 250 carries this season.

Considering he averaged over 4.8 yards per carry during the past two seasons while running behind one of the worst offensive lines in the league, he's likely to turn those carries into big time production. Combine that with his potential in the passing game and his nose for the end-zone, and you might just have a fantasy monster in 2016. With essentially no injury history on his record, Miller appears to be one of the most surefire early round running backs available.

Get him while you can -- he won't be underrated for much longer!