Why do we say that somebody who is with it, has a keen sense of what is going on, is competent and up to date, etc. is on the ball or has a lot on the ball?
In consulting my usual sources for this, I discovered that only one of them has written anything about it: Evan Morris, otherwise known as the Word Detective (see http://www.word-detective.com/090304.htmlon%20the%20ball. And yet the origin of the expression is not that easy to discern and there is at least one explanation circulating that is completely without founding.
To begin with where the expression does not come from. Visitors to the Royal Observatory and National Marine Museum at Greenwich, England, are sometimes regaled with this story, which is passed on as fact by some of the tour guides there. One of the buildings on that site, Flamsteed House, is adorned with two towers on the front facing of the central block (see http://www.nmm.ac.uk/server/show/nav.3483). One of these towers is surmounted by a mast, which in turn is topped with a weather vane. At 12:55 P.M. every day (except when it is too windy), ever since 1883, a large red ball rises to a point halfway up the mast. At 12:58 it rises to the top of the mast, and at precisely 1:00 o'clock it falls. Nearby residents and ships on the Thames used to set their clocks and watches by it, if they owned clocks or watches. According to the faulty etymology, this is the ball referred to in the expression: to be on the ball originally meant, so the story goes, to be exactly on time, and was subsequently extended to mean to have the very latest information, to be up to date. Presumably the meaning sometimes given to the expression, to be alert, can also be derived from the Flamsteed House ball: in order to know that it is precisely 1:00 o'clock one has to "keep one's eye on the ball": one has to see it actually fall. If the ball is in its normal position, at the bottom of the mast, it could be any time between 1:00 PM and 12:58 PM!
Unfortunately, as is the case with so many plausible explanations, the facts do no bear this explanation out. The first appearance in print of the expression did not occur, according to the OED, until 1912, and it occurred on the opposite side of the Atlantic Ocean, in the USA. And indeed, although the expression is now used on both sides of the Atlantic, the British perceived it as American for several decades. It derives from that most American of sports, baseball. Especially successful pitchers, those who were able to outwit and bamboozle the batters who came up against them, were said by commentators to have or to be putting a lot on the ball, "a lot" referring to what we now call spin, "English," etc. So said of a pitcher "He has a lot on the ball" meant that he is able to handle anything that comes up, he's on top of any situation that confronts him. And that's what it still means, even though the expression has now escaped the baseball stadium (and indeed, crossed the Atlantic)!
One of the morals of this story is: don't believe everything that tour guides tell you!
Apologies for the delay in postings: last week was spent marking essays and midterm examinations! If you have a suggestion for a future posting, please leave me a MySpace message or get it to me any other way you can think of!