Former No. 1 Spieth moves wrong way

PEBBLE BEACH — Moving Day on the PGA Tour is a fickle creature. The game’s top players often maneuver into position, occasionally rising from far back in the pack to suddenly give themselves a chance to win.

Jordan Spieth went the other way Saturday.

Spieth eventually will hoist a trophy again. He’s too skilled, too smart and too competitive to plunge out of sight, but that’s exactly what he did on a wet, blustery day at the AT&T Pebble Beach Pro-Am.

Paul Casey, conversely, climbed atop the heap. His 67 at Spyglass Hill moved him to 15-under-par 200 and gave him a three-stroke lead over Phil Mickelson (who shot 70 at Pebble Beach) entering Sun-

day’s final round.

Spieth, after falling into a tie for 18th, will complete his 34th consecutive tour start without a victory. He hasn’t won since the British Open in July 2017, a striking streak for golf ’s onetime golden boy.

He won five tournaments in 2015, including the Masters and U.S. Open. He won three more times in the first seven months of ’17, including the AT&T and that Open at Royal Birkdale, where his back-nine, final-round surge toppled Matt Kuchar.

Spieth spent 26 weeks in all at No. 1 in the world ranking. Now he’s down to No. 21 and searching for answers.

He planted himself in the hunt the past few days, until he played Saturday’s final six holes at Pebble Beach in 4over-par. That quickly, he signed for 74 and dropped from the thick of contention (tied for second) to a virtual afterthought.

“I’m very frustrated,” Spieth said after finishing with a bogey on No. 17 and double bogey on No. 18. “If I just go par-par (to finish), I’m essentially still in this tournament with what’s forecast tomorrow. I kind of threw myself out of the tournament.”

Spieth, to his credit, stopped to speak with reporters after his round. It would have been easy for him to stomp away, angry about his misadventures on the course. But he always has been poised and professional beyond his years — an old soul, as the saying goes.

His slump isn’t shocking in some ways, because Spieth, 25, soared to prominence despite modest power off the tee. Most elite, 21st-century players hit the ball a country mile. Spieth need only look at Dustin Johnson, the other pro in his group the past three days, for confirmation.

But Spieth became the world’s top player mostly because of his putting. He was ninth on tour in strokes gained/putting in 2014-15 and second in 2015-16; last season, he finished 123rd in the same category.

Steve Stricker, another player known for his work on the greens, insisted Spieth will rediscover his touch and resume jostling with Johnson and Co. for supremacy.

“He’ll come back,” Stricker said. “It’s the nature of the game, the ups and downs of golf. I think it’s a little unfair that we all judge Jordan off what he did his (third) year on tour, winning all those majors and tournaments. …

“He’s got a good head on his shoulders and a good support system. He’ll get it going again.”

Spieth was uncommonly wild off the tee Saturday, an issue he couldn’t overcome on the bumpy, rain-soaked greens. He pulled his tee shot into a tree on No. 13, leading to double bogey, and pulled another tee shot into the water on No. 18, again leading to double bogey.

Earlier, when a torrent of rain drenched the course for about 45 minutes, Spieth held it together with a string of pars. But he struggled to control his ball over the last six holes — and that cost him.

“It kind of stinks,” he said, “because I really had it going the last couple days and just didn’t have the same rhythm today.”

Mickelson, meantime, managed to stay in the fray as he chases his fifth Pro-Am title. He made four bogeys in his first 10 holes Saturday, then responded with a birdie on No. 13 and eagle on No. 14, where he hit his second shot (downwind, from 237 yards) to 3 feet.

Mickelson, at age 48, would make a strong statement — as in, he’s still a factor — if he catches Casey and wins Sunday.

Casey, a 41-year-old Englishman, is seeking only his third PGA Tour title. He spent several years on the European Tour earlier in his career, but he returned to Pebble Beach for last year’s AT&T and tied for eighth.

Now, after taking flight on Moving Day, Casey has a chance Sunday.

Ron Kroichick is a San Francisco Chronicle staff writer. Email: rkroichick@sfchronicle.com Twitter: @ronkroichick

Harry How / Getty Images Jordan Spieth, shown on the ninth tee Saturday, has dropped to 21st in the world after spending 26 weeks at No. 1.

Jeff Gross / Getty Images Third-round leader Paul Casey plays his second shot on the first hole Saturday at the AT&T Pebble Beach Pro-Am at Spyglass Hill. He finished eighth a year ago.