Good hits

If you guess a four seam fastball every time you will increase your chances of hitting the ball, and hit the ball further.
Easy home runs:

Start season mode. Press Start during a game and go to the options. Go to "User Game Tuning" then increase your contact and power until it is a full bar. You will now be able to hit a home run with almost every at bat.
Quick win:

Score a run then press Start. Go to "Fast Forward" and select "End Of Game". You will win.
Inside the park home run:

When you are at bat, if the ball goes to the entrance of a dug out, the opposing team will try to pick it up but will not be able to get to it. Keep running until you get to home plate.
Big ball:

Pause game play, then press Up, Right, Down, Left, Right, Down, Left, Up.
y dova.
Small heads:

Pause game play, then press Left, Right, Down(2), Left, Right, Down(2).
Game developer starters:

Pause game play, then press Left, Down, Up, Right, Left, Down, Up, Right.
Disable sound effects:

Pause game play, then press Up(2), Down(2), Left, Right, Left, Right.
Faster players:

Pause game play, then press Left(3), Up, Right(3), Down.
Faster pitch speed:

Pause game play, then press Up(2), Left, Right, Left, Right, Up(2).
Slower players:

Pause game play, then press Right(3), Up, Left(3), Down.
Big heads:

Pause game play, then press Left, Right, Up(2), Left, Right, Up(2).