AUGUSTA, GA. – To understand how Jordan Spieth set a 36-hole scoring record at the Masters, one could listen to him preach "patience," or one could watch him exhibit it on the 15th hole Friday afternoon.

Spieth would finish with a second-round 66, giving him a two-day total of 130, one shot better than Raymond Floyd managed in 1976. He will take a five-shot lead into the weekend in his bid to become the second-youngest Masters winner.

He is threatening to take a 9-iron to Tiger Woods' tournament record of 18 under, and he is doing so without the benefit of Woods' length or intimidating presence.

So how is Spieth conquering Augusta National?

Let's visit the par-5 15th to find out.

On Thursday, Spieth hit a solid drive to the top of the hill, leaving himself with a long shot to a tricky green. Spieth wanted to hit a hard 4-iron. His caddie talked him into hitting a fade with a hybrid. Spieth took the hybrid and hit it straighter and harder than he wanted to, launching the ball well over the green and under a tree.

Jordan Spieth walked off the the 15th green with a birdie and a score of 14 under par. He played it smart on No. 15 after bogeying the hole on Thursday.

A branch kept him from hitting a flop shot, so he wound up hitting a mediocre chip and three-putting for a bogey — his only bogey of the tournament. After the round, Spieth said he should have hit the 4-iron and trusted himself to carry the pond in front of the green.

Friday, Spieth arrived at the 15th tee at 13 under par, with a massive lead on the field. His playing partners, Henrik Stenson and Billy Horschel, were struggling around par. Spieth teed off first, and hit another drive down the middle, to the top of the hill, with a strong wind costing him some distance.

Stenson drove into the left rough. Horschel laid up in front of the pond. Spieth had a long discussion with his caddie, pulled out an iron, and debated himself for a few minutes before finally laying up, as well.

"It's tough, because I just want to hit hybrid," he said. "I want to get it on the green in two."

With Spieth waiting at the bottom of the hill, facing a tricky pitch shot to a fast green, Stenson smashed his second shot off a tree. The ball bounced into pine straw behind another tree. Stenson took a long time to mull his next shot, then hit a line drive into the embankment in front of the green, the ball bouncing back into the pond.

Stenson snapped his club over his knee and marched down the hill. Horschel and Spieth pitched onto the green.

Stenson took a drop, then walked over the bridge to look at the green, then walked back, mulled some more, and finally pitched onto the green.

Spieth knocked in his birdie to reach 14 under, the mark that would give him the 36-hole record.

One fan, watching the leaderboard, said, "Do they even have a red 15, or are they gonna have to write it on a napkin?"

To recap: A 21-year-old playing at a record pace on the only hole on the course he had bogeyed was forced to wait an inordinate amount of time to hit one of the most delicate shots on the course, and made birdie, and didn't complain about the wait.

He also chose the safe option when his competitive nature was telling him to go for eagle on a reachable par-5.

It's easy to say "patience." It's harder to practice it.

"The only problem was that I had to use the restroom," Spieth said. "So sitting around, waiting, sitting around not moving for that long didn't help."

Spieth is proving that power isn't necessary to overpower Augusta National. He's winning with accuracy, course management, calm and putting.

Throughout golf history, when a young powerhouse like Woods or Jack Nicklaus has thrived, the line has been: "He plays a game with which I am not familiar."

Spieth is playing a game with which everyone should be familiar. He hits it straight and makes putts, rarely even attempting the kind of daredevil shots that made Woods and Bubba Watson famous.

"He's definitely an old head on young shoulders, isn't he?" Stenson said. "He's playing strategically. He's playing very mature."

Spieth's 130 total ties the low for the opening 36 holes in the history of major championships. In 1997, Woods set the scoring record for the tournament at 18 under. Spieth needs to play only 5 under par on the weekend to beat that.

Last year, Spieth held the 54-hole lead at the Masters, and faltered as Watson won.

"What I learned was patience," Spieth said.

He needed a lot of it at the 15th on Friday.

Jim Souhan's podcast can be heard at souhanunfiltered.com. On

Twitter: @SouhanStrib. • jsouhan@startribune.com