Major League Baseball

Unhittable Pitch:
Place the crossarrow anywhere in the strikezone except in the yellow hitting circle.
Holding the crossarrow where you want it, press Z and then, Left-C, Right-C, or Up-C to look at one of the bases. Release the C-button first, then release the C-button, bringing you back to looking at the batter.
There should be now no cross hair or hitting circle.
Now throw whatever pitch you want and the computer will swing and miss or watch it go by as a strike.

Secret Teams:
Highlight 'Exhibition' on the first baseball (menu) that pops up.
Now simultaneously press all four C buttons. Do this many times and you will hear a beep.
Then go to All-Star Teams and there will be two more teams: Nintendo and Angel Studios.
Key Nintendo executives are actual players on the Nintendo team.

Move Title Screen Logo:
At the title screen hold Z to make the baseball in the logo stop spinning.
Keep holding Z and then rotate the joystick to make the baseball spin however you like.

Shoot Fireworks:
When you get into the "View Statium" mode by pressing the Z button while choosing your stadium, you can shoot fireworks by pressing the Z and R buttons at the same time. The fireworks shoot near home plate.
This code works in every stadium.

Blow up your batter:
This code must be entered quickly. When your batting press(on the D-Pad)Right,Left,Down,Right,Left,Up,Right,Left,Down, and you batter should blowup.
Don't worry he will reappear the next pitch.

Two strikeouts for one:
When you are pitching, let the computer get a runner on.
Then strikout the next batter, and as soon as the batter strikes out make the back catcher throw the ball to the base that the runner is on. If this trick is done correctly, you should have two strikouts added to your total instead of one. This trick does not work with two outs, so you can get up to five strikouts per inning.

See Opponent's Pitches:
Here's something useful: Press R on the second controller during a one player mode
to see the opponent's pitching status and pitches.

Player Dances:
Batter Dance - At the pitch/bat screen, enter the following on the batter's Control Pad: Up, Up, Down, Left, Left, Right, Right, Left, Left, Down, Up and Up. The batter will boogie!
Pitcher Dance - At the pitch/bat screen, enter the following on the pitcher's Control Pad: Up, Up, Down, Left, Left, Right, Right, Left, Left, Down, Up and Up.
Your hurler will throw some snazzy steps.

Wear Opponent's Uniform :
When you are playing the game and you are the away team, when you hit a home run wait until it shows your teammates cheering in the dugout.
Press the A button and the player's jersey will change to the color of the home team's color for a short while.
This will work in any mode except home run derby.

Know Opponent's Pitch:
To find out where the other player is aiming his pitch, simply press and hold bunt.
The pitcher's target will appear and your bat will follow it.
Release bunt when the pitcher throws the ball and hit it normally.