It kind of depends what someone's job entails. Many jobs of a collaborative nature require trust go both ways, and the subordinate may even be considered more integral to the company than the supervisor.

Terrible idea.

I don't understand. Why don't you ask the candidate technical questions relating to software, rather than random math questions?

I feel like software is a field that is much easier to evaluate somebody through an interview process compared to other fields. Unless when you say "software", you are talking about something else than what i'm thinking of.

Highly not recommended.

The two "left field" questions we use routinely are:
You have some spare time on your hands and decide you are going to watch a TV show. What site do you watch?
And
Your working at your desk, when you suddenly get hit in the back with a Nerf dart. What is your response?

I feel like they both serve a pretty straight forward propose - TV gets a read on your interests (without the standard "what do you do when you aren't working") and we have Nerf guns. And sometimes you will get shot. If your answer is duck and return fire, you are sitting pretty. (we did hire that guy)

I'm not a huge fan of random critical thinking questions for hiring because of many reasons already stated. The main one is that I don't think the answers to those questions really hold any accurate weight towards how the person would critically think through real questions in the real world. Real world, they have some knowledge on what they are making a decision about. Random question equals random luck.

Poker during an interview seems worse than asking a random question.

I'm currently an undergrad in college applying to finance jobs, so a different perspective from someone currently in the job hunt/interview process.

There is a trading firm in which poker is part of its ethos. A third of the summer-long training process for new hires involves learning and playing poker. They ask poker-related questions during all rounds of interviews. While they greatly like hiring poker players, they don't expect you to know anything about poker. For example, they asked me a question that was very obviously asking about pot odds, but they didn't call it pot odds. Knowing poker and what pot odds were greatly assisted me in answering, but anyone bright could have figured it out.

Asking the person to play a specific game that isn't even that popular anymore does not seem like a good idea. Are you hoping they already know how to play? If they don't, will you try to teach them? All the way down to the hand rankings and betting rules?

If you actually want to play a game, ask them if they know any poker games. If you want to use poker to test their problem solving skills, lay out a hand of hold em on the river, tell them they're facing a bet of $20 into $40 and see what they do. If they're bright, they'll figure out pot odds on their own. Then they can evaluate their odds based on whatever (doesn't actually matter if they're right or wrong, just how they think) and decide to call or fold.

Finance in particular is known for difficult technical, math, problem solving, brainteaser, and oddball questions, from the internship stage (source: personal experience) all the way up to the senior level (source: a relative used to be a senior recruiter at a major trading firm), so in that industry, I think OP is onto something with their idea. As for other industries, no idea if it'd be out of bounds or helpful at all.

This is really different from the scenario the OP described.

Everyone knows how to work a Nerf gun. Not everyone knows the rules of poker (think how many people don't know three of a kind beats two pair or a flush beats a straight). Nerf gun fights are not associated with any stake of consequence. Poker is associated with money and people will feel performance anxiety.

Most relevantly, your interest in Nerf guns is verifiable - that is, if the candidate gets mad and asks why you're asking such irrelevant questions, put a Nerf gun on the table in front of her and say, "no reason" sarcastically. If the OP's candidate gets mad and wants to know why he's asking poker questions, OP will have to answer "no reason" literally.

Excellent choice of music. It was my wedding song :-)

the idea sounds bad. but i dunno ive never been in a job interview or conducted one. i cant imagine working for someone else or doing their little dance for them to not get the job or however it works.

i prefer living stress free with my own hours and printin stacks

That was my point. Possibly, probably, poorly worded point. Even our "random" questions are still relevant and relatable. Just not necessarily a question you might expect to answer going into an interview.

Poker appears to be neither.