It's the greens, stupid.

That's the way Zach Johnson explains much of his success at the TPC Sugarloaf. He's won here twice, including last year in a playoff over Ryuji Imada. And he attributes much of his good fortune to the slippery bentgrass greens groomed by superintendent Mike Crawford.

"The greens are still bent, aren't they?" Johnson recently inquired.

Yes, they are, and few players have done a better job performing on them. At this week's AT&T Classic, the greens —- a combination of Crenshaw and Cato creeping bentgrass, for those of you keeping score at home —- will roll to an 11 on the stimpmeter.

"I think a lot of it is the surface," Johnson said. "If you were to look at the [PGA] Tour and the players on the tour and where they grew up and the type of surface they grew up putting and where they play well now as far as region, I think there will be some parallels."

Johnson —- just a Midwest guy from Cedar Rapids, Iowa —- grew up putting on bentgrass greens at Elmcrest Country Club. He enjoys the fast surface, which produces putts that roll true and hold their line.

"It's all about being comfortable," he said. "When you get on a course where you like the greens, you can see the line and feel the speed; it's just a dangerous combination."

In five appearances at Sugarloaf, Johnson has never missed the cut. He's won twice (2004, 2007) and tied for second (2006). His other finishes are a tie for 17th in 2002 and a tie for 26th in 2005. His career stroke average is 69.316, the best in tournament history.

And once he settles into a rhythm, Johnson becomes one of the best putters in professional golf. He jumped into the public consciousness at the 2006 Ryder Cup, when he played fearlessly and knocked in more than his share of critical putts.

The lid came off the secret in 2007 when he won the Masters.

"It's just a confidence train," he said. "Putting should be pretty simple, because it's a very simple motion. But it can beat you up and spit you out. It's one of those parts of the game that seems to frustrate players more than any other part."

The putting numbers haven't been as good for Johnson this year; he called it "a little bit sluggish." He ranks 147th in putting, averaging 29.68 per round, which partially explains his slow start.

Johnson has only one top-10 finish and ranks 84th on the money list. A return to Sugarloaf could be the proper tonic to get his season back on line.

"I'm anxious to get back to the form I was in last year or even better than that," Johnson said. "I think I can get better.

"I'm excited for the future."

TOURNAMENT WEEK

> Course: TPC Sugarloaf, Duluth (par 72, 7,259 yards)

> Field: Includes Retief Goosen, Stewart Cink, Charles Howell III, Camilo Villegas, Hunter Mahan, Greg Norman and defending champion Zach Johnson.

> TV: Today-Friday, Golf Channel, 3-6 p.m.; Saturday-Sunday, CBS, 3-6 p.m.

> Tickets: Available at the gate or www.attclassic.com.

TODAY-SUNDAY * TPC SUGARLOAF