Baseball Stars - Be a champ! © 1989 SNK Corp. of America.
North American version. For more information about the game itself, please see the original Japanese version entry; "Baseball Star - Mezase Sankanou [Model SFX-B9]
Description from the back cover:
Player, manager, owner... You can do it all in Baseball Stars! Make your own teams and leagues; hire, fire, and trade players; develop your players from inexperienced rookies into veteran pitchers and hitters. Play against a friend or challenge the computer - you'll never have to worry about being rained out again!