Spieth made his PGA Tour debut at age 16 at this event on this course and finished in a tie for 16th place.
That remains his best finish in the event as this is the final AT&T Byron Nelson to be contested in Las Colinas.
“I made five bogeys in the round through my first twelve holes which is just ridiculous out here,” Spieth said. “Then I still had a nine on 16. So many over par holes and not necessary, just trying to do too much and move up the leaderboard instead of just letting it come to me on this course.”
Spieth was in contention in last year’s Nelson, but a final round 74 dropped him to a tie for 18th.
“Last year I had a scenario where I could win going into the final round,” he continued. “But I felt like I really needed to make a move today or fall pretty far behind. I just tried to do it in the wrong ways and it set me back a little bit.”
Spieth is known as one of the best putters on the PGA Tour, but the short stick is part of his current struggles as he now gets ready for his title defense next week at the Dean & DeLuca Invitational at Colonial Country Club in Fort Worth.
“Just got to figure out my putting and getting through the ball,” he said. “I’m standing over it and I don’t feel like I’ve got a stroke that’s producing contact at the right time. I put in a lot of work this week. Cameron and I spent hours on the putting green and hours on the putting green from here at Dallas National, too. I’ve put in plenty of work. It’s just a thing in my head, I’ve just got to get a couple to go in and it just didn’t quite happen.”