The percentage of black players in the major leagues dropped again on Opening Day this year even as the sport again received a top overall grade for racial diversity. Baseball's grade for gender hiring declined slightly, according to the annual study released Thursday by Richard Lapchick's Institute for Diversity and Ethics in Sports at the University of Central Florida. Baseball received an A for racial diversity in hiring, the same grade as last year, and a B-minus for gender, down from a B. Its overall grade remained a B-plus. The percentage of black players dropped to 8.5 percent this year, down from 10 percent at the start of last season and its lowest level since 2007. The percentage of Latino players dropped from 28.4 percent to 27 percent, baseball's lowest since 1999's 26 percent.