Sometimes I’d see MLB players warming up by swinging their bats, but for some reason the bats have a ring or something on them in the middle. Is this to help them focus on the bat’s sweet spot? Wouldnt having an extraneous object on the bat in practice throw off your swing when you do it against a real pitch?
It’s a weighted donutto help them warm up before they go bat. Some players grab a couple bats and swing them around in lieu of the donut.
I almost knew that was coming.
The belief is that if you warm up with an artificially heavy bat (weighted by the donut), then when you swing an unweighted bat it will seem light, making it easier to achieve high bat speed which translates into harder-hit balls. Plus swinging a heavy bat helps to maintain muscle tone with no risk of failing a drug test.
And it looks cool, and has a long tradition, both of which hold a lot of sway with MLB players. I will say that it seems more players are just warming up with their regular bat these days and using the wait to time the pitcher, which seems like a much saner approach to me.
doesn’t the donut change the weighting characteristics of the bat. Moment of inertia maybe?
Not as cool as when Willie Stargell used a sledgehammer instead. 
Kids used to do this all the time back in Little League. I think the theory is that, you get used to swinging something heavy, then when you face the pitcher, you’ve tricked your muscles into thinking the bat’s heavier than it is, and by swinging it as if it were heavier, you give it the extra oomph required to knock the ball farther.
Immaterial. All you’re trying to do is trick your arms into thinking the standard bat is lighter than the weighted bat (or, as in Willie Stargell’s case, the sledgehammer.)
The donut does fool you into thinking the bat is heavier, so your swing is quicker and easier when you’re up to bat. We used them in high school when I played baseball, and I think it worked fine.
You can get them for golf clubs too.
Before the donuts, players swung multiple bats all the time. In addition to making the bat seem lighter when you get in the batter’s box, it allows you to warm up your arm muscles a bit.
ESPN used them in a commercial - a baseball player and a guy typing faster after taking them off his wrists. Anybody know the player’s name (for purposes of linkage)?
I use one on my fork when I know I’m going to have eat dinner really fast.