One-piece bats are more rigid and have less flex through the hitting zone, which makes them ideal for power hitters. Two-piece bats have more give/flex when the ball is hit.
When picking a fastpitch softball bat you want to get the perfect size and weight that fits you. Fastpitch softball bats range from 26 to 34 inches in length and have drops ranging from -8 to -13 which indicates the length to weight ratio. The key to finding a good Fastpitch bat is getting the perfect size and weight that fits you. The right bat is one that is comfortable and easy to swing. To find a good length, hold the bat with its knob in the middle of your chest. If you are able to grab the barrel of the bat with one hand, then it's probably a good length for you. At the end of the day, deciding on the weight of your bat comes down to what feels right for you and how strong you are.
Composite bats are constructed from a lighter material so the barrel can be stretched longer than a typical alloy bat without making the swing weight heavier. As a result, composite bats can hit farther and often with less effort than traditional alloy bats.
For most fastpitch players, a heavier softball bat provides greater power. However, lighter bats are better suited for smaller players who need faster bat speeds to compensate for their lack of strength.