answer:The answer to your question is in your details…. Unless you’re asking what the difference between a one-piece bat and a two-piece bat is? If that’s the case, a one-piece bat is composed of a single piece of aluminum (or composite metal, if you shell out a bit more cash). A two-piece is jointed at the middle, and composed of two separate pieces of metal. The idea is that when you swing to make contact with the pitch, the upper piece will snap a bit, creating a whip-like effect and adding a bit of pop to your hit. As far as which one is better, I’ll say this: I had the pleasure of hitting with a Stealth once, and it was the best bat I have ever used.