UK Game Show Golden Balls: A New Solution to the Prisoner’s Dilemma

Several years ago, Felix Oberholzer-Gee, Joel Waldfogel and Matthew W. White, published a fascinating empirical article about the prisoner’s dilemma game embedded in the short-lived U.S. game show “Friend or Foe.”  Their core findings:

Using data from two seasons of a television game show, we provide evidence about how individuals implement conditionally cooperative preferences. We show that (1) contestants forgo large sums of money to be cooperative, (2) players cooperate at heightened levels when their opponents are predictably cooperative, and (3) players whose observable characteristics predict less cooperation fare worse (monetarily) over time, as opponents avoid cooperating with them. 

I always thought it might be nice to update the study to test to see whether different kinds of “cheap talk” were more or less effective in establishing cooperation (ex. Does swearing an oath to God make your promise more credible?). 

It might be time for a follow up: The UK game show “Golden Balls” (sounds like an Austin Power’s character) ends with the same PD conflict – as two contestants have to decide after a 30-second discussion whether to “split” or “steal” the big prize. This clip shows a contestant who devised an amazing (but possibly not repeatable) solution to the dilemma:

Mike B

You stole this story from Bruce Schneier's blog. Shenanigans!!!

You can read his analysis here.

Here are some questions this raises.

1) Can this sort of trick work again.
2) Can you get the same outcome by convincing your opponent you are choosing randomly (ie pull out a coin and flip it). What about random choice with a promise to split post facto?
3) Can the players form a binding verbal agreement to split the money? They have witnesses and the agreement would be on tape.


The first time I heard about "Golden Balls", I told a co-worker that my strategy would be to tell the other player that I would give them 1/3 of the money, but I was going to steal. I would even go so far as to throw away the share option if it were possible (I'm not sure of exactly how the selection process works). I always wondered if anyone had employed that strategy.


This isn't a true prisoners dilemma because the cost of splitting when the other steals and the cost of stealing when the other steals is the same.


This isn't, strictly speaking, a Prisoner's Dilemma. Your payoff is the same (o) whether or not your partner defects. This strategy would not be as effective with a pure PD as there is a greater commitment problem for the proposer.


I feel a lot of the discussion glosses over the clip that this is not a true PD. In a PD, being betrayed is worse (for the person who cooperated) than the double-defect outcome. Here, if the opponent steals (defects) the outcome for you is 0 either way.

Moreover, its precisely this discrepancy that Nick's strategy exploits. If it were a real PD, convincing the other player that you would defect would simply cause them to defect as well. But here, Nick takes advantage of the fact that if he convinces Abraham he will defect, then Abraham is indifferent, since he gets 0 no matter what he does, and can be swayed to cooperate by even a small hope of an unenforceable gift from Nick.


There's already at least one paper written on Golden Balls:

Would be interesting to look into the "cheap talk" analysis, though.


The real Prisoner's Dilemma assumes no communication or side deals between the prisoners, because they're *prisoners.*

This is clever, but irrelevant.

Jim B

An important aspect of this strategy is that Nick ultimately chose the "split" ball. Had he done as he had promised, and chosen the "steal" ball, he ran the risk of losing everything (if Ibrahim had also chosen "steal"). In this case, his bluff had its intended effect and convinced his opponent to choose "split" as well. This was the optimum outcome, because the split was automatic. But choosing "split" gave Nick a shot at half the pot even if Ibrahim had chosen "steal". Nick could then make a strong moral claim for half of the pot that probably would have been honored - particularly because of the high cost of public shame if Ibrahim refused to share.


Interestingly, I think that the next time someone tries this then they HAVE to pick steal because if they don't their opponent will be able to steal the whole pot from them. I think that the idea that the public commitment might be considered a verbal contract is interesting also.


I thought this was very clever but I am confused about some things.

Does Ibrahim consider walking away with nothing (split split) the same as walking away nothing and Nick getting the money (split steal)?

If Ibrahim things that Nick will stay true to his word and pick steal but suspect he can't trust Nick, wouldn't he just pick steal so they both get nothing? I can understand how some players might think "at least one of us should get something" but I don't know how Ibrahim feels about it.


Watch the actual selection closely. I think that Ibrahim was truly convinced that Nick was going to steal, and thought, "well, screw it, if he's going to steal, he's getting nothing." But then I think he changed his mind! I think he resigned himself to the fact that even the slightest chance at half of the money (i.e., trusting that Nick would honor his promise to split) was better than none at all.


For goodness sake, pedants, it's not the classic Prisoner's Dilemma, but it is a variant of a larger class of games that are quite often labeled with that name. The difference is that the classic PD has a strong equilibrium, whereas this game has a weak equilibrium.

Caleb b

I spent 20 minutes trying to explain to my wife why this video was so awesome. I totally failed.

Mike MacDonald

Richard Nixon pioneered this strategy 40 years ago: convince your adversary that you are crazy enough to engage in mutual assured destruction, and then watch as he behaves nicely... and you do too.


I played this game in one of the personality development training's and it was real fun. On a serious note,I feel a better alternative to absolute competition is subjective complement...My blog has details of why I think so.


I think I am going to have to meditate on this for a while. What Nick did was absolutely brilliant; his goal was to ensure that Ibrahim would not choose steal and have Nick end with zero. I am sure that the life lessons for this are huge, I need to learn to integrate them into my thinking.

Alex Blaze

Christopher Ryan had an interesting take on the prisoner's dilemma a few years ago: Nash equilibrium is that neither confesses since the reward for one person confessing without the other isn't less prison, but getting shivved. It's part of a larger point about the enforcement of social norms.


While I understand that tack--gambling that the other guy would rather trust that you'll split the money than to chance losing everything--I don't think I would have reacted well to this sort of gamemanship. I'm afraid I might have chosen steal just to spite the guy for playing so aggressively...and then, if he's have still chosen split, I'd have won it all.

I think the audience would have taken a "he had it coming" attitude toward the guy if I chose to keep all the procceds after I chose steal and he chose split. He had brought on my reaction by his too aggressive play and deserved every bit of his comeuppance.

I'm afraid I'd have rather had my pride than the money. I'd have felt bullied. Further, if he HAD have chosen steal and hadn't split the money after promising to do so, I'm afraid I would likely have...well, I'll save that for the game.


So I am at work, browsing while waiting for a program to finish running - which is the most common time for me to have time for aimless browsing. I follow a link that seems interesting here, start reading. I get to the ending last paragraph:

" shows a contestant who devised an amazing (but possibly not repeatable) solution to the dilemma:"

And then what? Why, this!:

"Your organization's Internet use policy restricts access to this web page at this time.

The Websense category "Streaming Media" is filtered."

Wow! Thanks! That's so interesting, presenting me with that and no further descriptive text whatsoever!

Note that I am not blaming the netadmins at my workplace. I even can't really argue against this policy; it probably saves a bundle on bandwidth. In fact it seems like such a good idea I expect it is far more common than not. So what bugs me is the astounding obliviousness involved in talking about how iiiiinteresting something is and then presenting it in such a manner that a non-negligible portion of the audience won't be able to see it, won't even know what the whole thing even is - BECAUSE you couldn't be bothered to actually TYPE IT OUT A LITTLE BIT.

Text exists for a reason. Use it.