"out of left field" (Why "left"?)

[Gerald Cohen]

    I have received the following query:

>Can you tell me how the expression "out of left field' came into
>existence and has the meaning it has? It is obviously of baseball
>origin, but why not out of right field or out of center or something
>else? Why is out of left field associated with the unusual or the
>bizarre or the weird or the unexpected?

     _The New Dickson Baseball Dictionary_ (by Paul Dickson; NY: Harcourt, 1999)
says: "_left field_...Extended use:1. Things that are unusual,
unexpected, or irrational are deemed to have come out, or from, left
field. 'You'd think things are starting to look like they've got a
pattern, and all of a sudden there's something that comes...from left
field' (An investigator working on efforts to  determine the cause of
the explosion of TWA Flight 800, quoted in _Baltimore Sun_, Aug. 17,
1996).
2. The political left.'Canadian businessmen last week were playing
host to two more trade missions out of far left field.  In Canada
searching for business were one team of sales-minded Russians and
another of inscrutable Hong Kong traders acting as agents for their
neighbors the Communist Chinese." (_Time_ magazine, Jan. 20, 1961).
  3. A bad seat in a restaurant or arena. 1st use, 1948. 'Unless a
name is in the register, he is given a seat in left field" (Jack Lait
& lee Mortimer, _New York Confidential_)."

     In other words, Dickson has nothing conclusive. Would anyone have
any ideas?

---Gerald Cohen