Lost words

Somewhere along the line, I picked up the notion that when you go to see a play you should be able to hear and understand what an actor is saying, even when you're in the worst seat in the house, and even when the script calls for the actor to mumble, whisper, or speak in a dialect. Is this precept being imparted effectively to actors by their teachers and directors? Not on the evidence of the play I saw last night: A complicated script, some of it in a difficult dialect; a large cast, with a lot of young actors; and an unacceptably high number of lost words, words thrown away, spoken indistinctly, tossed casually and irrecoverably through the window of incomprehensibility. Although two or three of the individual performances were excellent, the overall effect was very disappointing.