Jikkyou Powerful Pro Yakyuu 4 (Japan) (Rev 1), 実況パワフルプロ野球4, is a baseball game developed and published by Konami for the Nintendo 64 in 1999. It was the fourth game in the Jikkyou Powerful Pro Yakyuu series. The game features realistic graphics, animation and sound, and offers a variety of game modes, including Exhibition, League and Tournament. The game also features a two-player mode, allowing players to compete against each other. The game also features a training mode, where players can practice their batting, pitching and fielding skills. The game also features a variety of teams and stadiums, and allows players to customize their teams by trading players and setting lineups. The game also features an in-game commentary system, which provides information on the game's progress. Jikkyou Powerful Pro Yakyuu 4 (Japan) (Rev 1) is an enjoyable and challenging baseball game that is sure to please fans of the sport.