Some running backs gave us a couple of eye-opening fantasy performances to look forward to in Week 4. Week 3 saw some of the best not live up to the challenge, and some of the modern rise to the occasion.

Having the right halfback in your backfield can tip the scale in a fantasy football owner walking away in Week 4 as a winner or loser. After three weeks into the season, we've gained a little traction in terms of knowing which backs can be the most productive versus which ones are worth less than the price tag they tote.

Picking a successful running back is critical. They're a quarterback's best friend when the passing game downfield isn't going as planned.

Here are our fantasy football running back picks for start 'em sit 'em in Week 4.

RBs to Start in Week 4

David Montgomery, Chicago Bears

The Chicago Bears are clicking on all cylinders right now. They're enjoying a 3-0 record while being tied for the first seed with the Green Bay Packers in the NFC North standings. Even so, the Bears ran into a bit of trouble when halfback Tarik Cohen went down with a torn ACL, ending the remainder of his play in this young season.

Montgomery hasn't had a shriveled season so far. He's rushed for more than 40 yards in all three games of the season. He's also been dependable in receptions, as he finished a Week 2 win against the New York Giants with 45 receiving yards while catching all three of his targets for one touchdown, making him a better bet in fantasy football.

His running game could improve in Week 4 as he's likely to see more touches in Cohen's absence. And yet, his receiving skills are where the Bears could really benefit. The Bears are in the midst of an offensive shakeup with Nick Foles now becoming the field general. Montgomery could benefit from this as he'll likely see more passes from Foles against the Colts.

Kenyan Drake, Arizona Cardinals

Steal? Check. Drake is in a great position to make some noise with the Cardinals right now. The future in Arizona is bright. The front office was already dangling a dazzling young duo in Kyler Murray and DeAndre Hopkins in everyone's faces. Now they've added a dark horse in Drake, which makes the torture to other teams just downright unfair.

Drake has done quiet well for himself through Week 3. Though the Cardinals last outing resulted in a loss, Drake rushed for 73 yards off 18 carries. In Week 2 against Washington he hauled in 86 rushing yards from 20 carries. In order for Drake to truly be successful, he'll have to generate more carries that result in touchdowns. If Drake continues to get more comfortable in an offense already brimming with talent, he could be a steal for most fantasy owners that didn't see him as a starter at first.

Alvin Kamara, New Orleans Saints

Coming into this tentative, often-jinxed season, Kamara knew his worth, and boy did it pay off. After holding out on his rookie extension until he received a dollar amount that felt right, Kamara has been proving that it was worth the wait. Though the Saints haven't necessarily shot out of a circus cannon to begin the season, that hasn't been to his fault.

He's rushed for 137 yards in his last two games, scoring two rushing touchdowns in Week 2 against the Las Vegas Raiders. Where he's really turned up his game though, is in his catches. He went off for 139 receiving yards while only missing one of his 14 targets resulting in two touchdowns on Sunday against the Green Bay Packers, bolstering his fantasy football value.

With nothing necessarily going right for the Saints right now, Kamara will continue to be the silver lining they draw from until they steady the ship in New Orleans. With that, it's easy to continue expecting big games from the halfback.

RBs to Sit in Week 4

Joe Mixon, Cincinnati Bengals

Mixon hasn't been able to help the Bengals overcome their early season woes. They broke even with the Eagles in Week 3 and currently sit at 0-2-1. Mixon has been conducive in that downfall.

The fourth-year back hasn't scored a touchdown in any of his first three games this season. He's only rushed for a total of 164 yards from 52 carries as well through Week 3. The shortcomings of his performances aren't solely his to blame, after being burdened with a talentless offensive line once again. His break out may come from opting for the passing game, as he's caught 77.8 percent of his passes so far into the season.

If the offensive line doesn't figure it out soon, the Bengals could have a long season in front of them, thus creating a nightmare for Mixon.

Adrian Peterson, Detroit Lions

Peterson put on a bit of a vintage performance against the Chicago Bears in Week 1 when he rushed for 93 yards off 14 carries. That performance hasn't resurfaced in similar fashion or excelled since. That's not to say that Peterson hasn't been productive for the Lions, especially given his age. However, averaging 3.4 rushing yards per carry as he did against the Cardinals in Week 3 isn't going to cut it.

He's yet to score one touchdown in any of the first three contests this season. If the Lions are electing to go forward with Peterson as their number one option in the backfield, that could prove to be a problem in the weeks to come. If Peterson can increase his output as an RB1, he'll more than likely find his way into starting lineups on fantasy rosters in the future.

Leonard Fournette, Tampa Bay Buccaneers 

Fournette has been catching a double-edged sword lately. Tom Brady has found his passing rhythm recently, and he'll more than likely continue that dominance to stay spry against the Los Angeles Chargers in Week 4. Fournette's role will more than likely diminish against the Chargers, a team that has been a nightmare so far for running backs in terms of fantasy points.

Fournette is averaging 5.1 rushing yards per attempt this season, partially due to a superb outing against the Carolina Panthers in Week 2. He finished that contest with 103 rushing yards from 12 carries along with two touchdowns. Though he's capable of those performances, it was mostly due to newcomers such as Brady and Rob Gronkowski still finding their rhythm on a new team. As the season progresses however, Fournette could see his snaps diminish. He'll also be competing with fellow halfback Ronald Jones II.