One way to cheat the system, especially in the playoffs, is to save your game, then configure your lineup and sim the results. If you lose, don't save. Reset the game and reconfigure the lineup based on their previous performance against that same pitcher. When you win, save the game again. Repeat to never experience defeat. It's the fastest (cheapest) way to win a World Series.
Easy strikeouts
Once you get two strikes on a batter, always throw a low inside curveball or slider. You will almost always get a strikeout. Get two strikes on a batter. This is easiest done with a curveball. Then, throw a cutter high and away (outside the zone). The batter will swing and miss for strike three. This only works with right-handed pitchers against right-handed batters. If the batter does not swing, use a low and inside curveball to finish him off.
Homerun hitter
At the main menu, go to "Rosters" to create a player. Enter the player's name as Erik Kiss. He will hit a homerun every time the ball is hit.
More broken bats
At the main menu, go to "Rosters" to create a player. Enter the player's name as Keegn Patersn, Jacob Patersn, or Ziggy Patersn.
Perfect game
Use Barry Zito or create a player that has a good slider and curveball. Throw the slider two times to the opposite side that the pitcher throws. For example, Zito is left-handed, so throw it to the right side (inside of a left-handed batter). This will cause the batter to think it is either to the inside or to the outside. The pitch must be at the edge of the strike zone. After that, throw a curveball in the upper inside or outside corner. He should strike out, pop out, or ground out.
Sucker The Padres
When playing in the franchise mode, the best way to improve your team is to trade for Oliver Perez of the San Diego Padres. You can trade a much less valuble player to get Perez, and he will be well worth it. Every franchise I've done I've got him for nothin and he's won multiple Cy Young Awards, never having an ERA over 3, plus he's in his early 20's. If you're gonna make any trades make it this one.
Trades
In season mode, the CPU will accept all your trades (at least in rookie mode). You can trade players that you do not use a lot for other players on other teams that are very good. For example it is possible to trade Marcus Thames to the Diamondbacks for Randy Johnson.
Cheat To Win...