1/2 Dozen (6) MLB Game Play Baseballs - New Commissioner Signature "Robert Manfred". Rawlings Official Major League Baseball. Rawlings, the official supplier of Major League Game Play Baseballs to all 30 Major League Teams, started producing the ROMLB in 2000. The ROMLB replaces both balls that were used in the American League and the National League (ROA and RON versions). Each baseball arrives new in Rawlings Box.