After two seasons in the Braves' farm system, in which he went 16–9 with a 2.51 earned run average, he reached the majors as a September call-up in 1967.

He made his major league debut on September 15 at Atlanta–Fulton County Stadium, and lasted just a third of an inning and giving up three earned runs against the Chicago Cubs.

He made just one appearance in the 1969 National League Championship Series, pitching one inning in the third, and final, game against the Mets.

As with the Braves, Stone began his career with the Mets as a relief pitcher, going 1–0 with a save and a 0.60 ERA before being added to the starting rotation.

[5] In 1974 and 1975, Stone was unable to match his early success with the Mets, going 5–10 with a 5.04 ERA, and ended up tearing his rotator cuff.