Jordan Spieth home at Nelson, which gave him confidence that he could succeed on PGA Tour

Jordan Spieth, left, and Martin Kaymer of Germany, shake hands at the end of the third round of The Players championship golf tournament at TPC Sawgrass, Saturday, May 10, 2014 in Ponte Vedra Beach, Fla. (AP Photo/Lynne Sladky) (The Associated Press)

Jordan Spieth finished 16th at the Byron Nelson Championship as a 16-year-old amateur. A year later, he missed his high school graduation ceremony after making the cut again.

Now at the ripe young age of 20, Spieth is the eighth-ranked player in the world. He comes home to the Nelson as the Masters runner-up and only days after playing with champion Martin Kaymer in the final group at The Players Championship.

Spieth says playing at the Nelson and having success there while still in high school "put an exclamation point" on that it was possible for him to play professional golf for a living.

The Nelson starts Thursday, when Spieth plays in the same group with defending champion Sang-Moon Bae.