by Jeff Owens, NASCAR Scene, Special to FOXSports.com

A lack of testing seems to have had a profound impact on the competition in all three of NASCAR's top series, especially the Sprint Cup Series.

Jeff Owens (NASCAR Scene)

How else do you explain the sudden drop in performance at Roush Fenway Racing, Richard Childress Racing and even Joe Gibbs Racing?

The continued dominance of Jimmie Johnson and Hendrick Motorsports is not a huge surprise; they have dominated the circuit for the past three years. But their prowess and superiority has only been enhanced by the ban on testing.

It's a move that had to be made, of course, so before we go much farther, it's prudent to note that NASCAR did a good thing by placing a moratorium on testing. And it is doing the right thing by extending that moratorium through next season.

NASCAR made the move for purely economic reasons. At this time last year, teams throughout the sport were struggling.

With the economy taking a nosedive, the sport's sponsorship pool was drying up. Sponsors already in the sport were looking to pull out or cut back. Teams were closing down and laying off employees left and right.

NASCAR had to step in and do something. Placing a ban on an expensive program that costs millions of dollars a year was, financially, a good move.

But NASCAR officials also knew they were taking a risk.

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A year later, it looks as if the downside of that move has been realized.

By prohibiting teams from testing at NASCAR-sanctioned tracks, the sanctioning body may have widened the gap between Hendrick and Johnson's No. 48 team and the rest of the competition.

No team in the sport was better prepared to adjust and react to the ban than Hendrick Motorsports, and especially the three-time defending champions.

It may be no surprise, then, that the only three teams still in championship contention with two races remaining are all Hendrick drivers — Johnson, Mark Martin and Jeff Gordon.

Those three have combined for 12 wins this year, four more than the next-best organization. Add in Tony Stewart's four wins at Stewart-Haas Racing, which benefits greatly from its close relationship with Hendrick, and it's clear that Hendrick and Hendrick-affiliated teams have dominated this season, winning almost half the races and so far claiming four of the top five spots in points.

The other drivers and teams that challenged Johnson last year have all struggled this season.

Roush led the series with 11 wins last year, with Carl Edwards scoring a series-high nine. Roush has won just three times this season, with Edwards going winless.

Perhaps even more telling is this: Matt Kenseth won the season's first two races for Roush, but hasn't won again and missed the Chase for the Sprint Cup for the first time in his career. Roush's third win as an organization didn't come until Jamie McMurray's upset victory Nov. 1 at Talladega.

Though Roush has two drivers in the Chase, Edwards and Greg Biffle both are winless and neither has been a factor in the playoffs a season after finishing second and third, respectively, in points.

Joe Gibbs Racing has also experienced a bit of a letdown. It won 10 races last year — eight by Kyle Busch. This year, Busch has four wins, but struggled so badly in the second half of the season that he missed the Chase and has already switched crew chiefs.

Denny Hamlin has won a career-high three races for Gibbs but once again has been no match for Johnson and the Hendrick teams in the Chase.

The organization that may have suffered the most, though, is Richard Childress Racing, which won three races last year and put all three of its drivers in the Chase for the second straight year.

This season, RCR has gone winless and none of its three drivers made the Chase. The organization has already made wholesale changes and Kevin Harvick, the driver for its flagship team, has flirted with leaving.

All three organizations — Roush, Gibbs and RCR — tested often in the past in an effort to keep up with Hendrick and challenge Johnson.

With no testing this season except at tracks that host no races in NASCAR's top divisions, it is understandable that they have fallen further behind, giving Hendrick an even bigger advantage.

There are exceptions, of course. Juan Pablo Montoya has made great strides at Earnhardt Ganassi Racing, as has Red Bull Racing, Michael Waltrip Racing and Richard Petty Motorsports.

But those are all rapidly changing organizations that have been going through growing pains and are finally starting to show some results. Imagine how much greater their progress might be if they were allowed to test.

To a lesser extent, the testing ban also may be a factor in the Nationwide and Truck series. Kyle Busch has once again dominated the Nationwide Series in Joe Gibbs equipment and is on the verge of clinching his first NASCAR title.

Ron Hornaday Jr., meanwhile, is putting the finishing touches on his fourth Truck series title, and his second in three years with Kevin Harvick Inc.

While the ban on testing was made with good intentions and for a good reason, it has clearly had an impact on the competition on the track, giving the top drivers and elite teams an even bigger advantage and making it more and more difficult for their challengers to catch up.

And with testing prohibited again next year, we may see more of the same.

Jeff Owens is a writer for NASCAR Scene, which is published weekly, 46 weeks per year. Visit www.scenedaily.com for more information.