Baseballisms

[Elster88]

The phrase "throwing beebees" generally refers to pitchers. Can any player throw a beebee, or just a pitcher?

[MFS62]

No. Not just pitchers.
I've heard it used to describe a fielder's ability to throw, too.
In fact, the White Sox had a shortstop called "Bee Bee" Richards.

Later

[Guest *62]

Jose Oquendo came up to the bigs with a cannon for an arm and the term was used with him, if I remember correctly, by Kiner and Murph.

[RealityChuck]

It's seem odd to use it to refer to anyone other than a pitcher. A BB is a tiny bit of shot used in kid's guns;* a pitcher throws BBs when the ball is traveling so fast it seems as tiny as one and hard to pick up to swing at.

If a fielder threw BBs, it'd mean the ball was hard to catch.

*"You'll shoot your eye out."