Quarterback Kirk Cousins hands the ball off to running back Rob Kelley in the third quarter of Washington’s victory over Minnesota. (Patrick Smith/Getty Images)

A year ago, the Washington Redskins emerged as a playoff team when quarterback Kirk Cousins transformed into an efficient, touchdown-generating machine. It was a dramatic ascension that enabled the franchise to skip a few rebuilding steps.

In the second half of this season, there are indications that a new, subtler force could boost the team back into the postseason. Introducing the latest candidate for savior: Rob Kelley, an unlikely standout even on this motley 53-man roster.

The undrafted running back out of Tulane — a 24-year-old so modest that he prefers his college nickname, “Fat Rob,” over his given name, Robert — is giving the Washington offense a seemingly simple dimension that could spur another dramatic improvement: consistency.

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Throughout all the struggles Washington has had converting high yardage totals into high scoring, Coach Jay Gruden has accentuated the positives while acknowledging the negatives, and usually his conclusion has been that slight adjustments, not a major overhaul, would make the difference.

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His offense is still far from where it wants or needs to be, especially when it comes to its much-maligned execution in the red zone. But since Kelley became the starting running back two games ago, there has been a significant uptick in the way the offense functions and attacks opponents. You can measure it in terms of balance, diversity of play calls and the manner in which Cousins and Co. are attacking most every area of the field.

Like Kelley’s game, the difference is understated. But it exists, and it’s spurring progress that the scoreboard should reflect soon. Simply put, the offense, which has averaged 467 total yards in Kelley’s two starts, is doing a better job of staying on schedule. That’s partly because the unit is showing better discipline and avoiding some of the silly penalties that stifle drives. And then there is Kelley, whose greatest skill isn’t speed or elusiveness but physical and instinctual running that results in consistent, positive yardage. He keeps Washington out of situations in which it succumbs to predictability or repeats old, bad habits.

“We don’t have a lot of negative plays,” Gruden said of Kelley’s impact. “You lose your play-action when you’re in second and 11, second and 12 and third and eight or you’re behind. We’ve been in games, in front, close games. We’ve been in second and manageable, third and manageable. So now your whole playbook is open, and that is the result of our running back not taking negative gains and our quarterback not taking sacks.”

In 60 carries, Kelley has rushed for negative yardage just twice. In two games as a starter, he has 43 carries and has been tackled behind the line of scrimmage just once. It was a loss of only one yard.

In his first start, he ran 21 times for 87 yards and a touchdown against Cincinnati in London. He followed that with an even better effort last Sunday, gaining 97 yards on 22 rushes against a Minnesota squad ranked third in the NFL in total defense.

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Kelley doesn’t look like former star running back Alfred Morris, and he runs differently. But his steady production is similar to the virtue of a young Morris. Kelley isn’t flashy, and he isn’t all that explosive. The offense has plenty of flashiness, and there’s potential to gain yards in chunks, even when wide receiver DeSean Jackson isn’t on the field. But it needed to get hard yards, to keep defenses guessing and to control possession for longer. So far, Kelley has specialized in providing just that.

The Washington Post's Scott Allen and Keith McMillan break down the Redskins' Week 10 win against the Vikings. (Thomas Johnson/The Washington Post)

Last Sunday, he had just three carries that went for less than two yards and just three runs that teams consider “explosive” plays (a 12-yard gain, a 14-yard gain and a 21-yarder). What happened on the other 17 of his 22 carries? His gains stayed between two and five yards.

In his 43 carries as a starter, 39 have been for positive yardage. Besides the single one-yard loss, he has three carries for no gain.

“I don’t dance,” Kelley said. “My goal is to get downhill as quickly as possible.”

This is what the offense has been lacking. Matt Jones, the team’s 2015 third-round pick, had provided plenty of “wow” plays. But he was too inconsistent. He didn’t always fight for the tough yards. He’s still raw, and he’s a chronic fumbler. Despite all the issues, Jones is still averaging 4.6 yards per carry, so the franchise isn’t going to give up on a young player with his body and ability to create big plays. But for now, Kelley is a stabilizing influence for this offense. He reflects how good the offensive line has become, and at times, he makes the line and tight ends look better.

Although General Manager Scot McCloughan and the scouting department now must listen to criticism for drafting Jones, they also figure to be proud that the roster has depth, and the spirit of competition is so strong that one miscalculation — or perhaps Jones is just experiencing a temporary setback — can be masked by the discovery of an unexpected gem.

Let me say it for the 99th time: McCloughan’s greatest value as a talent evaluator is his holistic approach and knack for finding talent in every place available. His success will be predicated not only on how many big things he gets right but how many surprises he uncovers.

Even Kelley is surprised right now.

“It’s okay for me to admit that I’m surprised,” he said. “It keeps me grounded. I won’t get the big head at all.”

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Washington has averaged 26.5 points in Kelley’s two games as the starter. It is still woeful in the red zone, scoring touchdowns just twice in its past eight opportunities inside the 20-yard line. I believe that this team, with its low margin for error, will make the playoffs if it averages 28 to 30 points the rest of the way. Pre-Kelley, it had been hovering below 23. Five or seven points make a huge difference in the NFL. The offense is inching closer to being a true representation of the 407.8 yards per game it averages, fourth best in the league.

With Jackson, the team’s greatest deep threat, on the mend, the offense could be even more dangerous if Kelley keeps forcing defenses to pay more attention to the run.

Few offenses are as good as this one at leveraging the run. Gruden’s system only needs opponents to respect the rushing attack. Once they do, anything is possible. The signs are already evident that Washington is turning into more than a nibbling, just-take-what-the-defense-gives-us offense. Who knew a 6-foot, 228-pound afterthought would have this big an impact?

It’s premature to say the Fat Rob era has begun. He would probably recoil at the suggestion, too. Still, for however long it lasts, his impact can’t be underestimated.

As football enters the cold-weather portion of the schedule, Kelley finds himself unexpectedly relevant to Washington’s postseason aspirations.