Idiom for random/arbitatry decision making [duplicate]

Question

Sometimes an entity's (be it a person, company, or a government) predictions/choices/decisions seem to be completely arbitrary (based on no evidence or observation).

A very colorful example of this is South Park's Margaritaville episode. When learning that a bank is going bankrupt, a board of judges or whatever decapitate a chicken, and throws its beheaded body into a pit divided into different areas with actions written on them, such as "Bail out", "Do nothing", "Pay $10000", "Sue", etc. The headless chicken runs around for a while until it finally drops motionless on one of the areas in the pit. The judges' verdict is based on where the dead chicken lands.

In Armenian we have an idiom "մատից հոտ քաշել", which literally means "to smell one's finger". Smelling one's finger, of course, does not give one any useful informations, so basing one's forecasts/choices on the "results" of smelling one's finger is completely random and arbitrary. For example, in Armenian one could say:

You can't trust the weather forecast. I think they simply smell their finger and come up with a prediction.

or

How does he know all this?
He doesn't, he just smelled his finger. (i.e. his claims are based on nothing)

or (in a maths class)

Teacher: Can a rational number raised to the power of an irrational number be a rational number?
Student: Yes.
Teacher: See, you have to prove it, you don't get to just smell your finger and answer yes or no.

Hopefully the South Park example and the մատից հոտ քաշել examples fully convey what situations I am talking about. So what idioms are there in English that can describe the arbitrary decision-making/choices?

Answer 1

"Eenie, meenie, minee, moe" is a childish idiom that denotes a random, arbitrary decision.

In randomly choosing one of two people to be on your baseball team, for example, you point at the first person and say "eenie"; you then point at the second person and say "meenie"; the first person, "minee"; the second person, "moe," and so forth. You do this rhythmically, as follows, with each finger-pointing represented by a slash/virgule:

"Eenie/, meenie/, minee/, moe/. Catch a/ lion/ by the/ toe./ If he/ hollers/, let him/ go./ Eenie/, meenie/, minee/, MOE."

The last person you point to (i.e., "MOE") is "out" and the other person is "in."

In the adult world, if someone were to ask you

"How did you come up with that answer?"

you could say, honestly,

"Well, I did 'eenie, meenie, minee, moe'!"

which means you chose randomly one of two (or more) possible decisions. (With three or more possible decisions, you do "eenie, meenie, minee, moe" several times until only one decision remains, and that one is your choice.)

Other idioms that come to mind include:

"So, did you pull that one out of a hat?"

In other words, each possible decision was put on a slip of paper; all the papers were thrown into a hat; and you pulled only one, blindly, from the hat; that one becomes your decision.

Or,

"What, did you use the magic eight ball for that decision?" (see http://web.ics.purdue.edu/~ssanty/cgi-bin/eightball.cgi),

meaning, did you just randomly ask a question of the magic eight ball by flipping it over and doing what it says? (The eight ball has a bunch of random answers floating around inside it, with a flat window at the bottom that reveals an answer once you turn the ball over.)

I used it at the website I cited by asking it "Should I use the magic eight ball as an illustration of how to make a random decision?" Guess what the answer was: "My sources say no." Despite its "decision," I obviously still used it as an illustration.

I asked the same question of the magic eight ball a second time, and this time the answer was "Absolutely!" You just can't count on that magic eight ball!

Answer 2

Someone who does this shoots in the dark,

or takes potshots at the problem.

The latter use is less common, as it more often is used to indicate a critical or callous remark made toward someone, e.g. criticism without much consideration for whether it is accurate.

---

More vulgar, people will calls these "wags", which is an acronym for "Wild Ass Guess"

Answer 3

I don't know if I would go as far as to call it an idiom, but the phrase "throwing darts" comes pretty close to what you want. Most people would at least understand it.

The idea references someone who posts a bunch of options on a wall and selects an option by wherever the dart lands. It's not something I really hear often anymore (as darts aren't as popular a game anymore), but I do hear it occasionally from older people.