Are softball bats considered carry on luggage or are you required to check them at tix counter?
I think you've gotten the answer to your specific question, but I wanted to point out another option: throw a layer of bubble wrap on it, put it in a box, ship it to the hotel you will be staying at, and ship it back home afterwards. I've done this in the past for out-of-state tournaments. I trust UPS far more than I trust the baggage handling staff/TSA at the airports. Even if it isn't stolen, in my experience there is a far greater chance of the bag getting misrouted and temporarily/permanently lost than with a third-party shipping service.