Deciphering which bat size is perfect for you is an extremely important task, but with our help, it is a simple one.
The first thing you want to figure out is which length suits you best. The best way to figure this out is by standing up straight and relax your arms by your side. Next, place the bat by your side as well. If the bat is the correct size for you, the knob of the bat should be somewhere between the palm of your hand and the top of your wrist. In terms of which bat length suits you best, this area is the sweet spot.
If the knob of the bat falls below or above this area, you will most likely need a different bat size. For example, if the knob of the bat falls at your fingertips, the bat is too short. Likewise, if the bat comes all the way up to your arm, then the bat is too long.
This is where things get a little fishy. Many companies will show you a chart based on your body weight and match you with a bat weight. This may work for some players, but the absolute best way to determine which bat weight is right for you is based upon your strength and what type of hitter you are. If you are a strong power hitter, you are going to be able to handle a heavier bat. If you are a smaller player who typically bunts, slaps or drags, then you may be more comfortable with a lighter bat weight.
Always swing what your arms can handle. One way to determine this is by grabbing the bat and holding your arms straight out. Your arms should be parallel to the ground. Hold the bat out firmly for as long as you can. If you can comfortably hold the bat straight out for more than 10 seconds, then this bat isn't too heavy of a load for you and should make a good fit. If you can handle a heavier bat, then always go with the heavier option. The more weight, the more power behind it. But, never get a heavier bat than you can handle because this could be detrimental to your swing and could compromise speed.
The barrel diameter will always solely depend on which league you play in and their specific bat regulations. The most widely accepted Fastpitch bat barrel diameter is 2 1/4» which is legal for ASA, USSSA, NSA, ISA, High School and NCAA.