Checking your swing is an advanced technique in MLB 2K9 that can help you avoid striking out and put the ball in play. To check your swing, you need to press the X button on the PlayStation 3 or the A button on the Xbox 360 and hold it down. The button needs to be pressed and held down before the pitch reaches the hitting zone. If you time it correctly, your batter will hold back on their swing and the umpire will call it a check swing. A check swing is not considered a strike, so it can be a valuable tool for avoiding strikeouts and getting on base.
Checking your swing can be especially helpful in two-strike counts. In 2K9, batters with two strikes are much more likely to strike out, so checking your swing can help you avoid making an out. However, it is important to note that checking your swing too early can result in a called third strike.