Here’s an interesting article in the Wall Street Journal. It’s about some studies of hitters who use weighted bats or doughnuts on their bats in the on deck circle. Turns out that, contrary to conventional wisdom, using a weighted bat for practice hacks does not speed up one’s swing when one uses a naked bat in the batter’s box. In fact, it slows it down.
There are lots of caveats here. The sample size in the studies are small and they all involve college and high school players, not big leaguers. The results, however, are consistent with previous studies and they do make some intuitive sense. This is particularly the case with batting doughnuts, which add weight to a very concentrated portion of the bat, thereby changing the center of gravity and thus the swing mechanics of the hitter.
Whether this is applicable at large or to higher level hitters or not, I still find it kind of neat. I always like it when people scrutinize ingrained habits and ask whether or not that thing we’ve always done is, in fact, worth doing.