“Writing it down matters for me,” he said. “It’s like a reinforcement.”

Image Ottavino’s notebook, which is for his eyes only. Credit... James Wagner/The New York Times

Ottavino does this exercise daily, using two pages of the notebook. On the right side, Ottavino details everything he did to care for his body and arm that day, from physical therapy to acupuncture, to keep his routine consistent. And if he pitches, he updates how much he threw and what he did after the game.

The left side of the journal is key for Ottavino, because it is where he works to maintain the mind-set he has worked diligently to achieve. At the bottom of the page, he writes down physical cues, such as “have a short circle,” a reminder to combat the tendency of his arm’s path to get too long, or “quiet body, fast hand," to help simplify his delivery.

At the top of the left page, however, Ottavino applies all the mental training he has learned in his 14 years of professional baseball. He usually writes this part during the early stages of a game so it will still be fresh if he is called upon in the later innings.

“It’s always important every day to remind myself of the thoughts I want to have when I’m pitching,” he said.

Being overly analytical has hindered Ottavino in the past. He described himself as “confident but paranoid” on the mound. “I feel like I fire off a lot of thoughts off per minute or per second,” said Ottavino, who was majoring in history at Northeastern University when he was drafted.

With the Cardinals, Ottavino worked with several mental skill coaches to help calm his mind. Even now, he said, it can still be difficult to push aside thoughts about the consequences of mistakes, like “if I give up a hit here, it’s two runs.”

“They try to tell you get to that spot of in the zone where you’re having no thoughts,” he said. “But I’ve never found that to work. I can’t get to that.”