MIAMI — The scoreboard operator at loanDepot park couldn’t even guess what new Mets starter Kodai Senga was throwing half the time, so the pitch types were often oddly labeled on the center-field scoreboard as “UNKNOWN.”

The three-time Nippon Professional Baseball All-Star and two-time Pacific League Best Nine winner’s many pitches — including the famed ghost fork — proved something of a mystery to the Marlins hitters, as well, as he won his Mets debut 5-1 to send the team on to Milwaukee in good spirits. That ghost pitch is more than a marketing tool but a real offering that accounted for all eight of his strikeouts, according to one website claiming it could identify the unusual pitches.

Senga’s varied pitch mix was tough to catalogue and even harder to hit, it turns out. His final line in 5 ¹/₃ innings revealed three hits, three walks, eight strikeouts and one clock violation. It was must-see pitching mastery and portends a fun next half decade, assuming he can stay healthy for all of his five-year, $75 million contract.

Officially, Senga’s perplexing and unique repertoire is a four-seam fastball, a forkball (we call it a ghost fork, as it disappears, even if Mets manager/curmudgeon Buck Showalter stubbornly refuses to call it that), a sweeper (maybe closer to a slurve than slider) plus a cutter.

When Senga was done with his dominant debut, he left to a standing ovation from most of the visiting crowd, Mets fans thrilled to see that the team may have another star for their rotation. Typical of well-heeled New Yorkers, this is like a second home for the Mets.

Afterward, Marlins hitters, also suitably impressed, were reliving the difficulty he put them through. They were speaking in Spanish, but thanks to my four years of learning (mostly C’s) at Lawrence High School on Long Island, I was able to at least identify the language if not the words. They see Senga as a future star.

“I think he’s going to be one of the best in the league in the years coming,” Avisail Garcia told me later in English. “I think he’s going to be great.”

“As advertised,” Jacob Stallings said. “The stuff was good.”

Showalter once again declined to call the killer pitch a ghost fork, though it was clearly the one that saved the day. No one on the Marlins quite admitted they didn’t see it. But Stallings came the closest.

“It’s tough to pick up,” Stallings allowed. “He struck me out on a splitter, whatever you want to call it.”

Based on outing No. 1, Senga’s adjustment to a bigger baseball, a steeper mound, foreign soil and all the new rules seems pretty seamless. In game, Senga’s performance went from shaky to superior in a hurry. But from the over-amped 99 mph fastball that started his day to the 84 mph ghost fork (at least we think it was a forkball) that struck out Jazz Chisholm Jr. to start the sixth inning, the stuff played.

“He has really good stuff. He’s throwing in the upper 90s and he’s tough to pattern,” the Marlins’ Joey Wendle said. “He has a lot of pitches, and a lot of stuff going in different directions.”

It wasn’t just the repertoire but the resilience. Senga’s first four batters went single, double, walk, walk before he shook off the expected nerves and showed folks why the Mets gave him $75 million over five years. He was overexcited at the start.

“Definitely a lot of nerves,” Senga said. “My legs felt like a ghost.”

Indeed, through that first quartet of hitters, you started to wonder whether this might be a long five years. But he quickly recalled that he was a decorated champion in Japan and Olympic gold medalist who posted a sub 2.00 ERA last year for the Fukuoka SoftBank Hawks.

Jon Berti’s liner to right field ended the scary first inning with the bases loaded when well-placed right fielder Starling Marte caught the drive, bringing noticeable relief for Senga, who allowed only one more hit and one more walk before Showalter pulled him with one out in the sixth. There was a meeting four batters in, but it’s a positive sign he self corrected quickly.

“I’m proud of him,” Showalter said.

Meantime, the Marlins were wowed by him. After that first inning, the contact was limited to little. Afterward, Marlins hitters were trying to decipher what they had seen. Garcia believed he faced every type offering, from the ghost pitch to the hard stuff. While Wendle at first called it a splitter, he recognized it had less velocity than most splitters and kindly accepted the ghost moniker. He said the one he saw was a bit up in the zone, and it was only the ones that were down that had “the ghost action to it.”

All this talk about ghosts, it was fitting that the Mets were off to Milwaukee, where they were to stay in baseball’s nice but known-to-be haunted hotel, the Pfister. Like with Senga’s calling-card pitch, the ghosts aren’t seen there either, merely experienced.