"I attribute my performance (in the Ryder Cup) to motivation," he said. "I wasn't willing to put in enough work to play good golf."

Rested and excited about playing, Mickelson has won the FBR Open in Phoenix and the AT&T Pro Am at Pebble Beach by posting two of the lowest scores of his career.

He shot 60 in the second round of the FBR and won at 17 under par. He shot 62 in the first round of the AT&T and won at 19 under.

The Tour's researchers think he's the first player since Johnny Miller in 1975 to post double-digit under-par rounds in consecutive events. Miller shot 61 at the Tucson Open and the Phoenix Open.

Mickelson had a career season in 2004, winning the Masters and coming within five strokes of sweeping all four majors.

This year he's playing with three pieces of prototype equipment, which won't be available to the public until this spring, some time between the Masters in April and the U.S. Open in June.

They are a driver made of carbon composite and titanium; a putter made to duplicate the putters he has used in the past, and a golf ball that's given him distance on long shots and control on short ones.

The Callaway engineers are especially pleased with what they've created in the driver. The composite material gave them 35 grams of weight to move around.

In Mickelson's case they moved it near the face and toward the hosel, creating a center of gravity that matches his swing. He tends to hit down on the ball while most players hit up on tee shots. The changes enabled him to launch the ball high with low spin, creating distance.

Of the three pieces of equipment, Mickelson says the ball is most significant to his success.

A new manufacturing process makes the core of the ball perfectly centered, and a lighter cover gives it more feel.

"It has given me back the 15 yards of distance I sacrificed last year for control," Mickelson said, "and I've picked up a couple more yards."

In 2003, a season in which he didn't win a tournament, he averaged 306 yards off the tee. Last year he averaged 295.4, and this year he's averaging 297.1.

His driving accuracy was better last year (62.9 percent to 58.7 percent), and his average for greens in regulation is about the same — 69.5 last year to 69.9 this year.

"The biggest difference for me last year was that I had to get control of my shots from 150 yards in," he explained. "To do that I went with a softer golf ball, and I sacrificed a lot of distance for it."

Mickelson believes the distance he has been driving the ball is one reason he has posted the lowest scores of his career.

In November he shot 59 in Hawai'i to win the PGA's Grand Slam. This year he has scores of 60 and 62, the latter at Spyglass Hill, which ranks as the fourth-most-difficult of the 12 courses played so far this season on Tour.

Mickelson returns next week at the Accenture Match Play Championship in California, then comes east to Florida, playing his way back to the Masters, April 7 to 10.