Leading up to his 2017 victory in California, the American had won eight PGA Tour titles, including two major championships, on the back of world-class putting performances, particularly from outside 20 feet.

In 2015 and 2016, he ranked ninth then second on the PGA Tour for strokes gained in putting.

When he won the 2017 Open Championship aged 23, Spieth was on a steeper trajectory of major championship wins than Tiger Woods at the same age.

But the putter has cooled significantly and former World No.1 Spieth is without a win worldwide in 19 months.

The 25-year-old could use another reminder of how he used his underrated ball-striking to win at Pebble Beach two years ago.

"It was really the first tournament I remember winning strictly with my ball striking," Spieth said on Wednesday. "I struck the ball incredibly that week."

Spieth went on to claim another PGA Tour win in June of 2017 before notching his third major title at The Open.

"(Pebble Beach) was big for that season because I felt if my putting was off, I could still win. If my ball striking was off, I could still win," Spieth said.

RIGHT: Spieth during a practice round ahead of the 2019 Pebble Beach Pro-Am. PHOTO: Cliff Hawkins/Getty Images.

Although a solid iron player, Spieth's lack of power when compared to bombers such as Dustin Johnson led to a reputation as unremarkable from tee to green but spectacular with the putter.

"I think (people) look at the major championships first and key moments; I think that's why," Spieth said.

"I was second to Jason Day in strokes gained putting (in 2016); anybody who leads the Tour for a year is going to be looked at as a great putter for a long time."

Spieth recorded two third-place results last year, including the Masters, but failed to lift a trophy as his putting rank plummeted to a lowly 123rd.

The Pebble Beach Pro-Am is Spieth's third event for 2019 and he believes a march back to winning forme could start this week.

"I've seen a lot of improvement with my putter over the last six months," he said.

Former World No.1s Jason Day and Adam Scott headline a nine-strong Australian contingent this week while two-time Pebble Beach winner Johnson and five-time major winner Phil Mickelson are also in the field.

- Evin Priest, Australian Associated Press