Smoltz is the first pitcher to win 200 or more games and save 150 or more. That unique career accomplishment undoubtedly propelled him to Cooperstown in his first year of eligibility.
On Wednesday morning during a festive occasion at the posh Waldorf-Astoria, Smoltz joined Randy Johnson, Pedro Martinez and Craig Biggio as the Hall of Fame Class of 2015 was officially introduced.
Smoltz, who grew up a die-hard Tigers fan and was in their system until he was traded to Atlanta in 1987, was always a hard-throwing starting pitcher.
In fact, during Smoltz's first 12 seasons with the Braves, he won 157 games. In 1996, he won the National League Cy Young Award when he was 24-8, with a 2.94 ERA. He was the best power pitcher the Braves ever had.
But during Spring Training 2000, Smoltz tore a ligament in his right elbow and underwent Tommy John surgery in March. He missed the entire season. That's what led to four summers in the bullpen.
"Coming back from the Tommy John surgery, it wasn't working for me as a starter," Smoltz said, still wearing his spanking new Hall of Fame uniform top. "I was suffering from tendinitis and had to go on the disabled list. I just couldn't see myself starting the rest of the year. I told Bobby, 'I'm going down to the Minors and try to help us by pitching out of the 'pen.'
"Bobby didn't agree. He said, 'No, I'm going to wait for you to start.' I told him I couldn't do it. So, I went to Greenville, S.C., and rehabbed. After I pitched three games in a row, I returned to the Braves -- working out of the 'pen."
Smoltz was throwing 97-98 mph and began relieving in the mid-innings before working his way up to being the Braves' closer the last month of the season.
And then came what turned out to be the biggest decision of his baseball career.
"The organization decided I was going to be their closer," Smoltz said, frowning. "That was a tough thing to take. It wasn't my popular choice. I struggled with the decision. I really thought I was going to the Yankees. I wasn't thrilled about [taking on the closer's role], but was willing to do it and stay to help us win a championship. "
And there was a moment when Smoltz asked himself if he'd made the right decision.
"When I came back as the closer, I gave up eight runs in two-thirds of an inning against the Mets," he said. "I got booed. Everyone questioned whether it was really going to work. I struggled the first month, but ended up leading the league in saves with 55."
That set an NL record that was later equaled by Eric Gagne.
"Really, I wasn't afraid to fail, and even if I did fail I was going to learn from it," Smoltz said. "That mindset and determination kept me going."
During Smoltz's 3 1/2 seasons as a reliever, he earned 154 saves in 168 opportunities. He was continually hampered by arm injuries, suffering from right elbow tendinitis in 2003 and undergoing minor right elbow surgery in October 2004.
"After three years in the 'pen, they asked me what would make our club better and I blurted, 'Me as a starter,'" Smoltz said.
Braves general manager John Schuerholz questioned whether Smoltz could make the transition back to starting.
"He wondered if it was even possible," Smoltz said. "'How do we know if you can pitch 200 innings?' he asked. It was a little brash of me, but I said, 'Take my baseball card and turn it over.' For 14 years, I had done that and knew I could do it again.
"I knew it was going to be a tremendous challenge, and I was going to be second-guessed and people were going to have their doubts. But you know, in both transitions I quieted the critics pretty early."
Jeff Nelson, formerly an outstanding reliever with the Yankees and Mariners, said moving from starter to reliever is not that difficult.
"But to go from starter to reliever back to starter again is hard to fathom," he said. "You go from one mindset to another, and that's not easy."
Smoltz said: "People who had never done it were experts all of a sudden. They said, 'This is not possible; you are crazy.' Guys who'd done a little bit of both said, 'There's no way he's going to be able to do this.'"
Much like Smoltz's first game as a closer in 2002, returning to the rotation in '05 was forgettable.
"I gave up six runs in 1 2/3 innings in my first start. I was so nervous," he remembered. "I told myself, 'Everything's going to be fine.' And it was. I was 14-7 that year and made the All-Star team. I always thought back to 1991, when I was 2-11 then went 12-2 in the second half."
From 1991-2005, the Braves won 14 consecutive division titles and John Smoltz was in the middle of it all. In 41 postseason games, he was an uncanny 15-4 with a 2.67 ERA and a record 199 strikeouts.
It's more than fitting that Smoltz is joining his manager, Cox, and former teammates Tom Glavine and Greg Maddux in Cooperstown. And it won't be too long before Schuerholz, the best GM in baseball history, makes it.
"When John was on the mound, you always thought you were going to win a ballgame," said Cox, inducted into the Hall of Fame last year with Glavine and Maddux. "The big games, the postseason and those games near the end of the season, you always felt you were going to win when Smoltzie was on the mound."
As a starter, and as a reliever.
It didn't matter. Smoltz made the full circle, and it ends in Cooperstown.
Hal Bodley is the senior correspondent for MLB.com. Follow him @halbodley on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.