There’d be no Iron Mike, polarizing legacy and all, without Cus D’Amato.

Who else could have taken in a troubled 14-year-old Mike Tyson and convinced him he’d become the youngest heavyweight champion ever?

“Cus had all the psychological makeup,” Tyson told amNewYork. “No one could have done it but him. No one knew me. No one knew how to make my trigger tick.”

Tyson’s new book, “Iron Ambition: My Life with Cus D’Amato,” is set to release Tuesday and follows D’Amato from his childhood in the Bronx to his renaissance as Tyson’s trainer and legal guardian in upstate Catskill. It was there that D’Amato taught Tyson his patented peek-a-boo style and instilled a warrior mentality in Tyson, a Brooklyn native, that struck fear in his opponents.

The book also discusses D’Amato’s fight against the mob-influenced stranglehold on boxing in the 1950s and ’60s, painting a complex picture of a man hell bent on giving those loyal to him, such as former heavyweight champion Floyd Patterson, a fair shake. It’s Tyson’s second collaboration with author Larry “Ratso” Sloman.

Fifty wins and 44 knockouts later, Tyson doubts anyone but D’Amato could have propelled him to championship glory.

“How could they handle me at my lazy moments when I said ‘to hell with training’ and I didn’t want to train?” Tyson said. “That would’ve been difficult for these guys. Cus knew how to talk to me. He made me love training.”

Reading “Iron Ambition” leads to an inevitable question: What would Tyson’s legacy be if D’Amato, who died in 1985 at age 77, were alive for the duration of his in-ring career? For starters, Tyson believes infamous promoter Don King would have never gotten close to him. Instead, he and D’Amato would have ruled boxing, taking out any opponents in their path.

“There wouldn’t be no Don King because all of his fighters would’ve been destroyed,” he said.

Despite his controversial career, Tyson attributes nearly all of his success to D’Amato, who instilled a sense of strict discipline in a life that lacked structure.

“He saved me, he saved my life, period, that’s all,” Tyson said. “He was an amazing man. I can’t even explain it. He was a godsend.”