Even with only three semesters of college before he decided to try to make a living playing golf, Jordan Spieth is good at math.

With four birdies and a pair of tough pars on the final six holes Friday in the Hyundai Tournament of Championship, he shot a 9-under 64 to build a four-shot lead in the first PGA Tour event of the year. More startling was the total score — 16-under 130.

That's only one shot off the 36-hole record at Kapalua set by Ernie Els in 2003. And there's more. Els won that year at 31 under, making him the only player in PGA Tour history to finish 30 under or lower in a 72-hole event.

Can he beat that.

Spieth figured he was 16 under through two rounds.

"I guess we're capable of doing 32, right?" he said. Then he looked up as he if was doing the math and said to himself, "Carry the one ... Yeah, that's right."

Yes, it can be done.

Except that he can't predict if he'll make putts and keep bogeys off his card. He doesn't know how the course will play or what the weather will do. But he knew one thing.

"If I got there, it would make for a stress-free finish," Spieth said. "Very likely."

He's smart enough to realize that 36 holes means he is just as far from the finish line as the starting line.

Kevin Kisner, coming off a big year of his own, shot a 65 and was in the group four shots behind that included Patrick Reed (69) and Fabian Gomez (66). Rickie Fowler was six shots behind. Bubba Watson and Brooks Koepka were nine shots behind. Nothing is settled.

SPIETH IN THE LEAD: Spieth suggested at the start of the week that with his five victories and two majors last year, his name means a little more when it's on the leaderboard. Presumably, it means a lot when he's four shots clear of anyone else.

But for all he has done, he has a 2-3 record with the 36-hole lead. He was five clear at the Masters during his wire-to-wire win. He was tied for the lead with Patrick Reed through 36 holes at the U.S. Open and went on to win.

He had a one-shot lead after 36 holes at Torrey Pines in 2014 and didn't win. He was tied for the lead through 36 holes at Pebble Beach and Congressional in 2013 and didn't win. He was just a kid then.

KAPALUA KARMA: Spieth is making only his second appearance in the Tournament of Champions, and he must like what he sees. Through six rounds, he has never been worse than first or second (he was tied for second, three shots behind, after two rounds in 2014 and finished one shot behind that year).

Asked to explain it, Spieth had a reasonable answer.

"A smaller field helps," he said, again showing off his match skills.

There are only 32 players in this winners-only field this year. Sometimes, how many players you have to beat is a better measure than who they are.

It was reminiscent of a question to Tiger Woods at the Presidents Cup in 1998. Woods had won three straight U.S. Junior Amateurs and three straight U.S. Amateurs. He lost his Ryder Cup singles match in 1997, and then lost to Mark O'Meara in the final of the World Match Play Championship a year later.

Woods was asked the difference between match play as an amateur and match play as a pro.

"The field," he said.

KISNER BACK: Kisner won the RSM Classic at Sea Island in the final PGA Tour event of the year, and he hasn't done much since then (except for a trip to Augusta National on Dec. 20 with swing coach John Tillery).

"I gave him 10 shots. He shot 80 and I shot 70," Kisner said. "And he complained the whole time that he wasn't getting enough strokes."

He was pleasantly surprised with his 69-65 start on a course he had never seen (and won't see anything like it the rest of the year). What helps is the Bermuda grass, which Kisner grew up on in South Carolina, minus the ocean views.

Spieth was pleasantly surprised to play with Kisner in the third round. He is good company.

"He's going to give me crap, which is what he has always done," Spieth said. "I run into Kiz most of the time in the workout trailer. He's in there all the time. And he brings out the good conversations that are had in there."

ODDS & ENDS: Dustin Johnson tried to rally from his opening 73. He missed a 4-foot putt on the 18th and still shot 66, so he's making progress, though he remains nine shots behind. Johnson's brother and caddie, Austin, had an injury and couldn't work, so trainer Joey Diosalvi has filled in. ... Spieth and Reed played the opening two rounds and combined to shoot 28 under with no bogeys on either card. Their better-ball score would have been 63-61.