NEW YORK—Eighteen former NBA players were charged Thursday with pocketing about $2.5 million illegally by defrauding the league’s health and welfare benefit plan in a scam that authorities said involved claiming fictitious medical and dental expenses. “The defendants’ playbook involved fraud and deception,” U.S. Attorney Audrey Strauss told a news conference after FBI agents across the country arrested 15 ex-players and one of their wives in a three-year conspiracy that authorities say started in 2017. According to an indictment returned in Manhattan federal court, the ex-players teamed up to defraud the supplemental coverage plan by submitting fraudulent claims to get reimbursed for medical and dental procedures that never happened. Strauss said prosecutors have travel records, email, and GPS data that proves the ex-players were sometimes far from the medical and dental offices at the times when they were supposedly getting treated. In one instance, she said, an ex-player was playing …