Many times I’ve been at wood bat tournaments or games providing demo bats and selling and had a player ask “Do you make any with bigger barrels?”. It is usually a younger guy who has grown up swinging tin (that’s what my Aussie friends call metal bats) with the big barrels needed for their trampoline effect. There are also many who have in their mind that a bigger barrel is going to make good contact easier.
The fact is, in the range of barrel sizes you will find on wood bats, there is no difference whatsoever in the ability of one size over the other to make good contact. This is because there is only about a 1″ to 1.2″ area (height wise) on the face of the bat where contact with the ball must be made for it to have a chance of being a hit. See the drawing below. It's physics - the Law of Reflection.
As you can see, above or below a certain point, and you’re out. There is no discernible difference between barrels in the area where you have to do business. There are lines you have to stay between to make bats. The harder and stronger the wood, the heavier it is. If you make bats out of good strong wood you have to make the barrel a little smaller or the bat becomes too heavy to swing. MLB recently banned bats made from certain species of wood because they were too low in weight/density. Guys were having bats made of this junk wood so they could get bigger barrels. There was lumber chunks flying every where. No one ever taught them that it makes no difference. A-Rod uses a bat with a 2.48″ barrel. He seems to be able to connect just fine. Little Leaguers swing a 2-1/4" barrel and also seem to hit just fine. So, don’t worry about barrel diameter when looking at wood bats. Keep your focus on the important stuff. Bat speed and control are the keys.
In all the years that I coached, it was a given that kids would want to use a “bigger” bat. I guess in their minds it meant that they were bigger and stronger and a bigger bat would mean bigger hits. Using too big of a bat just means LESS hits.
Here is how it works. There is no free lunch. A given player is able to generate just so many foot pounds of force. If you could start using a bigger bat and swing it at the same speed as the smaller one, then yes, bigger hits. But since you only have a certain amount of strength, when you swing a longer bat (higher moment of inertia) your swing speed is slower. Bigger bat, more mass, slower bat speed, the ball goes X feet. Smaller bat, less mass, faster bat speed, the ball still goes X feet. It is essentially a wash. If you want to hit the ball farther and harder, it’s simple, get stronger.
The upside to swinging a shorter, or lower MOI, bat is that it allows you to wait a hair longer on pitches to be able to recognize them better AND to adjust as you swing a little better. Those “hairs” and “little bits” can many times be the difference between a hit and an out. Remember, baseball is a game of inches. At the end of the day, here is how you should look at it - swing the biggest bat you can control and still get around with control against the fastest pitching you will be facing. This doesn't mean in the cage where you can time it up and the machine isn't trying to get you out. Real pitchers - with skills.
The other reason I hear for wanting to use a longer bat is for better plate coverage. I’m sorry, but this reasoning just plain doesn’t work for a couple of reasons. First, whatever part of an inch you gain on the outside of the plate, you just lost it on the inside. Second, hold your fingers up and look at an inch between them. I guarantee that you vary how close you stand to the plate by a lot more than that. Tony Gwynn, who won 7 National League Batting titles, and Barry Bonds both swung a 32-1/2″ bat. They seemed to have covered the plate pretty good.
If I made a prioritized list of 20 things that were important in being able to be a good hitter, I think barrel size and bat length would be 18 and 19.
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