Second guess

Gee, Don1, I think second guess is an assumption that may or may not be warranted. I'm not sure why a second guess is different from a "first" guess. That character could as easily say I'm not gonna try and guess what this defendant is thinking.

This has a different slant on the phrase -- but I think, in the example you gave, the "2a" description is closest to the right meaning.

According to this:
The American Heritage® Dictionary of the English Language: Fourth Edition. 2000.

second-guess

TRANSITIVE VERB: 1. To criticize or correct after an outcome is known. 2a. To outguess. b. To predict or anticipate: “She can second-guess indictments” (Scott Turow).
INTRANSITIVE VERB: To criticize a decision after its outcome is known.
OTHER FORMS: second-guesser —NOUN

Hi Piffka, this is why it has me baffled, why not just say "I'm not gonna try and guess" it's the word second that has me stumped

My little Oxford Colour Dictionary says it means:

Anticipate by guesswork or criticize by hindsight.

I think we can safely say that the writers on the show may not be quite as adept as we might wish.

Don and Piffka, I think it's rather like second sight, but I'm guessing.

second guess: to guess what people think or what they will do

Example: "Don't try to second guess people. Ask them what you need to know."

From English Idioms

I've forgotten my grammar lingo, so someone else can probably explain it more technically. But the verb "second-guess" is used immediately before the object.

So it would be "I'm not going to second-guess the jury" instead of "I'm not going to second-guess what the jury is thinking."

mac, I don't think it helps to know the grammar, but for what it's worth, "to second-guess the jury" is an infinitive phrase with "the jury" as the object of the phrase. The entire phrase is the object of the main verb, "going".

Second guessing is like Monday-Morning-Quarterbacking--the person who indulges in second guessing has information not available to the people who made the decision in the first place.

Thanks!