There is a serious flaw with the game's AI. When the CPU's team has a man on third, you can pick him off easily almost every time because he gets too much of a lead from the base. Press B+RIGHT to throw to third.
When you're on defense go to the pitchers view and pick any pitch. Then, before you throw the ball push right on the Control Pad, then throw a pitchout (Y Button). The computer will never swing and you can strike him out every time you try.
Note: This only works for a right-handed pitcher against a right-handed hitter.