The game of “would you rather?” can be a lot of fun (and it’s a great way to propose absurd, rude or gross situations where one option is as bad or worse as the other). What people might not realize when they do it is that it’s a perfect example of a classic thought experiment. 

Thought experiments are ones like Schrodinger’s cat or the trolley problem, used to question physics or debate ethics. 

Here I present a way to look at the cards on the table: Schrodinger’s hand. 

Schrodinger’s Cat

This particular thought experiment proposes that a cat is placed inside a box together with a decaying radioactive substance. The cat is both dead or alive simultaneously until you open the box to observe it – and when you open the box, the cat is automatically dead. 

What it proves for physics is that matter can exist in several states at the same time: It’s also used for some examples to illustrate the multi-verse theory, where the cat would exist in a different state in every universe at the same time. 

But what it proves for cards is how to consider an opponents’ hand. 

Card Games, AI and Hidden Information

Bridge has far more hidden information than poker or blackjack. 

This is part of what makes bridge a harder game for an AI to find its way around than regular blackjack or the average poker table (and part of why Facebook’s poker experiment taught us anything at all about how AI is able to learn).

Hidden information are things like cards that are face down: The hand of an opponent, for example, especially in relation to your own

This hidden information I’d like to call Schrodinger’s Hand. 

Schrodinger’s Hand

Any unseen partner or opponent’s hand can be called Schrodinger’s Hand.

Why? 

The cards are either dead or alive: They exist in both states – good or bad for your game – until you’ve either seen them in play or figured out what they’re going to be with some success. 

When they become observable (either by coming into play, or by the player having an idea what these cards are), they are now in a different state than they were before. Metaphorically dead or alive. 

When you think of unseen hands, the first objective you have as a player is to figure out which cards these might be – and how they relate to your next move. 

An approximate idea of what the other cards at play are right now – and who the players are holding them – gives you a better idea of which cards you’re going to have to play now or keep for later.

It can lead to thoughts like, “I hold two of the aces and my partner appears to have the other. This leaves one that still has to come into play at some point. Now what?”

When in the middle of any card game, consider the elements that you can see versus the elements you can’t. If you learn how to put these together, you’ll have a much better idea of what could potentially happen next.