One Piece vs Two Piece
One piece bats have less flex and are more durable. Two Piece bats have more flex and less vibration, creating a whip effect for faster bat speed. Two piece bats are great for players who want to increase their bat speed or power. If you are a player who still needs to work on your mechanics, remember the more miss-hits you have on a two-piece bat increases your risk of breakage.
End-load vs Balanced
Hitters who want more power tend to go with an end-loaded bat (more weight in the end of the bat). But if you drop, hit too many pop flies, or have an undercut swing, try a more balanced bat.
If you are able to get a few swings with the bat, how does it feel? Does your swing feel too slow? Then you may need a smaller/lighter bat. If it feels too light, go with a heavier bat.