Hold Left Analog-stick Up for a better chance of hitting a homerun. This works well when using a power hitter such as Sammy Sosa, A-Rod, Frank Thomas, etc.
Easy Perfect Game
Go to the game play setting sliders and go to 'AI batting'. Set everything to 100 and the CPU will never swing the bat.
Stealing Bases
99% of the time, if your lead off hitter is fast egnough he can steal. If the other team has a cannon of a catcher stay there. If you are a rookie, try not to lead off because it is difficult to get back on base not getting off. If a player is at third and the hitter hits the ball, wait until your opponent catches it. Then, steal from third base to home plate. If you have a person on second and third base, make the batter bunt (only if you have no or one outs) and go home and to third base so that the batter gets a sacrifice bunt RBI.