indeed, in some variations of pocket billiards you *must call all of your shots. cf.
The Hustler, the classic pool movie starring Paul Newman and Jackie Gleason. they played 'straight pool', wherein after 14 (of 15) balls have been sunk they are re-racked and the 15th ball is shot in such a way as to either break up the rack (usually with the cue ball) or to leave the cue hidden behind the rack (called a safe shot or safety). in the latter instance you have to call 'safety'.
The Billiard Congress of America (BCA) calls this game "14.1 Continuous"
-joe (i am not a shark) cool
http://www.bca-pool.com/play/rules/rls_141.shtmlp.s. - what you see on TV these days (at least on ESPN) is almost exclusively 9-ball. (see the link for official BCA rules) amazingly, in 9-ball you *don't have to call your shots. but. if you can't run the table off the break (which implies not only being able to call your shot, but being able to plan how you're going to run out after the break!) more than half the time, you won't win on TV.
