Major League Baseball 2K9 is a simulation of the sport of baseball, where the heart of the game lies in its franchise mode. Players can guide their team through whole seasons with hundreds of matches, managing key aspects such as player balance and making trades. The ability to study extensive statistics, negotiate contracts with free agents, and hire players adds depth to the managerial side. However, trading is handled differently, where every club assigns a value to its players on the roster, affecting the negotiation process.
The gameplay allows for both simulated matches and manual control. Pitching requires precise input using two parts of the controller: aiming and movement. Batting involves swinging at the right timing to influence ball direction. Fielding is controlled by guiding the player in the desired throwing direction. Players can also participate in training, Home Run Derby, and Postseason mode, with unlockable training cards.