The most sought-after DLC added new historical boxers not included on the base disc. These included:
Fight Night Round 4 was released in 2009. Its DLC included: fight night round 4 dlc pkg
The term “PKG” refers to the PlayStation 3 package file format (.pkg). Official DLC from PSN comes as a .pkg file that must be installed (and often requires a license/rap file). The most sought-after DLC added new historical boxers