What does "a" mean in "playing a in the dark" in the Twitter tweet quoted below?"'We all dance around in a ring and suppose but truth sits in the...

With regard to "tweets," as anyone can publish them, it's
hard to get a good take on the content. It's nice that Robert Frost's poem, "A Secret
Sits," is alluded to, short though it may be.

Stallone's
line, "life is playing a in the dark with NO referee pal...",
probably reflects nothing more than a typo. I have not seen slang
used with "a." I have read some of Mr. Stallone's messages to get a sense of the kind of
writer he is, and based on his style, I'm guessing it was an inadvertent
slip.

Perhaps I assume too much, but if he "tweeting on the
run," the way some of us text-message, that "a" may simply be slip of the...thumb,
(rather than tongue).

Your question makes perfect sense,
but I believe "a" is simply a mistake—though I wouldn't presume to tell you that I know
for certain. Don't worry that it's "only" a tweet: the only "silly" question is one
never asked. Above all, I hope this clarifies the text's content for
you.