The 2015 U.S. Open champion finished over par in three of his four rounds at Pebble Beach. He's traditionally struggled at this event. His victory four years ago is the only time in his career he's posted a score under par.
Spieth's performance Sunday didn't go off the rails until he made the turn. The Texan did open with a bogey on No. 1 before rebounding with birdies on Nos. 4 and 6.
This year's tournament has been notable for Spieth, though not in ways he likely would have preferred. He was heard chastising his caddie, Michael Greller, on the eighth hole in the first round.
"I didn't give myself enough time to go through my normal routine today," he said. "I did a little early session and then from there I went in and ate lunch instead of putting, and it didn't pay off today."
It's particularly notable because Spieth's short game has been a source of frustration all season. He ranks 161st on the PGA Tour in greens in regulation (63.99 percent), and his putting gets worse as tournaments go on.
Per PGATour.com, Spieth leads the circuit in putts per round in the first round (27.40) and second round (26.53). That average drops to 136th in the third round (29.17) and 112th in the fourth round (28.92).
During the final round, Spieth couldn't recover from those previous struggles to make up any ground. He buried himself by going five-over par over a six-hole stretch on Nos. 9-14, including a double bogey on the par-four 10th hole.
Following a brief sigh of relief with a birdie on 16, Spieth closed out Sunday with back-to-back bogeys. He shot 41 on the back nine, his worst nine-hole stretch of this year's tournament.
Getting on the green was an area of frustration for Spieth in the final round. He was just 8-of-18 (44.44 percent) on greens in regulation, tied for his worst percentage of the weekend.
One of the most distressing things about Spieth's performance at the U.S. Open is it came as he appeared to be rounding back into form. He came into Pebble Beach with three consecutive top-10 finishes, including a third-place showing at the PGA Championship last month.
Prior to that run, Spieth's last finish inside the top 10 was at the British Open last July. The 25-year-old has been trying to find his previous successful formula for a long time. His current streak of 45 straight tournaments without a victory is his longest since turning pro in 2012.
Cathy Marino, Spieth's coach at Dallas Jesuit College Preparatory School, told B/R's Tully Corcoran she can't pinpoint what's gone wrong with his game.
"It's still a mysterious thing, somewhat," Marino says. "I've encountered a lot of really good players that look great, they hit the ball so good, they even look like they have really good short games, and they just don't score as well. It's fascinating."
An optimistic perspective to take is that Spieth has rarely found success at the U.S. Open, so his showing this weekend doesn't have to be alarming.
Given where Spieth's game appeared to be headed coming into this weekend, it's a fair point to make. His progression will have to be a steady one since there doesn't appear to be any singular answer for what ails him.
Spieth's age and past success make it difficult to give up on him completely. The U.S. Open was a hurdle that he failed to clear, but he still has one more chance to win a major when the British Open begins on July 18.