Shohei Ohtani began the 2023 season with a twist: calling his own pitches through a PitchCom device hidden underneath his jersey near his left shoulder. The new look, with Ohtani appearing to jab at his armpit before each pitch, was the only departure from his usual dominance.

He threw six shutout innings against the Athletics in Oakland on Thursday night, striking out 10 and allowing just two hits. He was occasionally wild, walking three and throwing just 55 strikes in 93 pitches. And, in a familiar refrain, he left with a 1-0 lead in a game the Los Angeles Angels would go on to lose 2-1 after Oakland scored two runs in the bottom of the eighth off reliever Aaron Loup, who recorded just one out and called it “probably the most embarrassing outing of my career.”

Ohtani’s decision to call his own game, a move prompted by the restrictions of the pitch clock, appeared to hit a glitch immediately; before his second pitch of the game, catcher Logan O’Hoppe had to call time to ask him to reenter the code on the device, and O’Hoppe quickly ran out to the mound after Ohtani threw his next pitch. For the rest of the inning, the two returned to the prehistoric days, with O’Hoppe giving Ohtani signs.

Ohtani said the breakdown got him out of his rhythm, and O’Hoppe said, “He probably could have been more unhittable if we had PitchCom in the first inning. You want to go to a different pitch, but you don’t have enough fingers.”

The communication resumed to start the second inning, and Ohtani settled into an efficient groove. When he is in charge, he is nothing if not certain. He frequently keyed in his pitch selection before the pitch clock even began, and on foul balls he reached under his arm and called the next pitch before receiving the baseball. After the fifth inning, home-plate umpire Adrian Johnson paid him a visit.

“He told me I was pitching a little early,” Ohtani said. “Before the batter was in the box.”

Ohtani was in trouble just once, in the fourth, with one out and Aledmys Diaz on third and Seth Brown on second. He then struck out Jesus Aguilar and Ramon Laureano in rapid succession, with Laureano swinging through a 101 mph fastball.

“That sequence right there,” Mike Trout said, shaking his head. “He went from dominant to unhittable.”

(There’s always a statistic to tell the story of Ohtani and the Angels: According to MLB’s Sarah Langs, there have been 25 previous times an Opening Day pitcher struck out 10 and allowed 0 runs. In those games, the pitchers’ teams were 25-0.)

Ohtani’s move to call his own pitches deprives the world of one of the game’s unique pleasures: Ohtani, wearing a quizzical look, incessantly shaking off his catcher. However, the pitch clock combined with the vast array of pitches at his disposal necessitates the adjustment.

“Shohei’s got so many pitches he can throw,” Angels manager Phil Nevin said before the game. “So for him to go through ’em and shake and shake and shake — time’s running out because that thing doesn’t say it quick enough sometimes.”

Major League Baseball approved the use of PitchCom for pitchers just a week ago; instead of the catcher keying in the pitch selection and the pitcher hearing it through a speaker in his cap, the sequence is reversed. Other pitchers, mostly relievers, are using the device to call their own pitches but placing it on their non-throwing wrist or forearm, where they can easily see the numbers as they type them in. Ohtani’s use of PitchCom is different — because he can’t see the numbers, he had to memorize the keypad to make it work.

It was a night of new rules; Ohtani singled to right in the fourth inning, his only hit of the game, on a hard grounder that undoubtedly would have been an out before the shift was outlawed. Ohtani called it a sign that left-handed hitters will no longer be at a disadvantage.

“It’s an even playing field now,” he said.

A’s manager Mark Kotsay said of Ohtani: “It’s great as a fan. You have to see it. He throws 100 and then steps up to the plate and hits the ball where he wants to. What’s not to like?”

ESPN staff writer Paul Gutierrez contributed to this report.