After you select your pitch, move your cursor towards the batter and press Y.
Easy Homeruns
Use the cursor and put it exactly in the low middle.
Harder Swing
Before the pitcher makes his selection, press R. When the pitch is thrown, your cursor will become small. If you hit the ball it will either be a home run, or a very hard hit.
Hidden Options
At the team selection screen, press X to display an options screen that allows you to change such things as the difficulty, weather, stadium, and time of game.
Intentional Walk
After you select your pitch, move your cursor away from the batter and press Y.
Perfect Pickoffs
Do the pickoff move. Then, as fast as possible (start selecting the "pitch" BEFORE the graphic even comes up), do the pickoff move again (try over if you must). If you do it fast enough, the runner will not lead off far enough, and will OVERRUN the bag coming back! Position your infielder over him, and he will be tagged out... every time. Great for "correcting" those fielding blunders we make sometimes. [Qualifiers: I have only tried this, so far, on the "Pro" level and against a CPU opponent.]
Reset The Count
While batting with a runner on any base, have the runner attempt a steal. Either go through with the steal or send him back. Quickly press Y before the view returns to your batter to reset the count to no balls and strikes.
Stealing Bases Easly
While a runner is on base make him lead off right before the pitcher is ready to pitch it like when he let's go of the ball repeatly press the X button on your controller he will be able to steal 2nd, or third easly you got to be quick.
Trading Trick
It's pretty well known that trading in WSB2K2 is pretty darn strict, but there's a pretty neat little trick to get all the trading you want. Go into season mode and when you select the number of players, select the maximum 30. Now, you can have full control of every team allowing you to make all the trades you want for any team.