By Mark Lamport-Stokes
PACIFIC PALISADES, California, Feb 16 (Reuters) - It took Bill Haas a long time to work out how to play Riviera Country Club effectively at the Northern Trust Open, but for the past two years he has certainly come up with the right formula.
Twelve months ago, he edged out fellow Americans Phil Mickelson and Keegan Bradley to win the prestigious title at the second extra hole and this week he will take a commanding three-shot lead into Sunday's final round.
Haas has always loved the challenge of Riviera, one of the classic layouts on the PGA Tour, but had finished no better than joint 22nd in his first five starts at the event, including missed cuts in 2009 and 2010.
"Even before last year when I did not have the best of records here, it was certainly a week that I penciled in on the schedule if I could get in and play here," Haas told reporters after firing a seven-under-par 64 in Saturday's third round.
"It's fun to play. I like everything about Riviera ... the golf course, the grass, just how it's an old-school style golf course.
"Walking in the locker room, seeing the pictures of all those champions on the wall, it's just got a great feel of it about it."
Conditions were extremely tough on Saturday with the course running fast and firm under a dazzling sun but Haas stayed patient and made the most of his opportunities when they came to post a 12-under total of 201.
"Temperature-wise, it was fabulous but with that some of the fairways are really running out, the greens are difficult to hit and it's getting firmer and firmer," the 2011 FedExCup champion said after mixing five birdies with an eagle at the 10th.
"Just because it's playing shorter doesn't mean it's necessarily playing easier. Today I was able to save a shot here and there, make a couple of nice par saves. I hit some really nice chips from around the greens."
Haas, a four-times winner on the PGA Tour, has several big names in hot pursuit with U.S. Open champion Webb Simpson and 2011 Masters winner Charl Schwartzel three strokes adrift, and world number three Luke Donald a further shot back.
"It's very difficult in this game to just pull away from the rest of the field," Haas said of the task facing him in the final round. "You've only seen a few guys ever really do that ... guys like Jack Nicklaus, Tiger Woods, Phil Mickelson.
"I've just got to try to stay in the moment, don't let my emotions get the best of me, try to get off to a good start.
"The guys behind me are going to make birdies and will certainly get closer at the top, so I've just got to try to hang in there and give myself a chance on the back nine."
The 30-year-old American is experienced enough to know that good form can never be taken for granted.
"Every day is a new day and you're always working," said Haas, whose distinguished golfing lineage includes his father Jay, a multiple winner on the PGA and Champions tours, and his great uncle Bob Goalby, best known for winning the 1968 Masters.
"My dad always said, 'When you're playing well, you're not far off from playing poorly; and when you're playing poorly, you're not far off from playing well.'
"There's just such a fine detail in your swing that can change daily, so you just always keep working on it." (Reporting by Mark Lamport-Stokes; Editing by Frank Pingue)