Mailbag: Double DFB

[Note: The publishing schedule got screwed up due to a mistake on our end. To not crowd out any posts, the next few posts will come out Thursday, Friday, and Saturday morning.]

After years of hearing you talk about DFB, I finally bought it. Then I joined the facebook group and it seems like most of the ideas there are a variation on this:

  1. Force Tom Cruise

  2. Force Pepsi

  3. Show the audience a picture of Tom Cruise holding a Pepsi.

What is going on? Is it just a lack of creativity? Or is this really the best use for the app? —OL

First, I agree with you. I find this sort of usage for DFB to be particularly uninspired. I’ve only been on the DFB Facebook page a couple of times and I do find it odd how many posts are a celebrity holding a playing card or something like that. It’s not that forcing a celebrity and forcing a playing card and then showing a picture of them both is a terrible trick (it’s a 3/10, but not a 1/10). But if that’s a trick you wanted to do, do you really need to go on Facebook for inspiration? You can literally do it with any celebrity holding any object.

Hey, here’s a new trick. You can predict Rihanna and a tin of popcorn.

Hey, here’s another new trick I just came up with. You can predict Lady Gaga and the game Clue.

I’m an endless fountain of “new tricks.”


With a list of 100 items, the odds that you get it right are 1 in 100.

With two lists of 100 items, the odds you get both right is 1 in 10,000.

So, mathematically, the double-prediction should get a stronger reaction.

But spectator’s reactions aren’t so finely tuned to the actual impossibility of a prediction.

In my experience, spectators really only sense the impossibility of something happening in three general buckets:

  • 1 in a few

  • 1 in a lot

  • 1 in a million (in other words, 1 in a number that is too large for them to conceive of).

An effect that is 1 in 100, vs an effect that is 1 in 10,000 isn’t really that different to people. They’re both just “1 in a lot.”

So if there’s a significantly better reaction to a reveal of Tom Cruise vs a reveal of Tom Cruise holding a Pepsi, I would guess it’s because the second one is more of a surprise to them. If I ask you to select a random celebrity from a list and then I show you I predicted it, you might be fooled, but you probably saw the ending coming. If I force Tom Cruise and Pepsi on you, you might expect me to have predicted them both, but the nature of the reveal is a surprise. A surprise ending gets a better reaction, even when the trick is identical.

Years ago, we tested something like this in our focus group testing. The publisher of this site went through a phase where he would write his predictions on his palm or arm in UV ink—ink that only shows up under a UV light. They make a number of markers of this style that write in this ink and have a built-in light in the cap of the marker.

So we tested a card trick, where the prediction was written on a piece of paper vs the prediction written on our palm in UV ink and the reactions were vastly improved when the prediction was written in UV ink. (I don’t have access to the precise testing data at the moment. But in my head I remember it averaging out to be about 30-40% higher reaction scores.)

So I think what people are responding to with the double reveal is more likely the surprise of the reveal rather than improved impossibility of the effect.

But there’s a big downside to the double reveal, in my opinion. It takes a trick that could be remembered as being about anything, and turns it into a trick that is about lists on your phone.

For example, something I used to do a lot with DFB when I visited a friend’s house is I would leave a bottle of ketchup (or something) in their mailbox or at their front door when I was coming in.

Later in the evening, I’d mention this new “fucked-up delivery service” I was using that was “super cheap financially,” but “sort of asks for more than you might expect in other ways.”

“Technically, I don’t think you’re selling your soul… per se…. but, man you won’t believe how fast the service is!”

Then I’ll demonstrate the service by improvising some little ritual like maybe drawing a symbol and burning it or something like that.

Then after that, I have them “randomly” select something from my grocery list. I take their hands and mumble some incantation under my breath, then look up and clap my hands together and say, “Let’s go look!” And this thing they chose just seconds ago is now waiting for us there in front of their door or in their mailbox.

There’s something almost sinister about a single bottle of ketchup on your front porch after I lay out that storyline for the trick.

Now, I promise you this is stronger than forcing Ed Sheeran and ketchup and then showing them this picture.

It just is.

Sure, if the premise and presentation you’re using is boring, then a double-prediction is probably better than a single one.

But if we’re just talking, “What are the strongest uses of DFB,” then any trick you have where the phone and the list are tangential to the effect rather than the focus of the effect is going to be better.

If you have your heart set on a double-prediction, I’d use two forcing methods. For example, I’d have them choose ketchup from my shopping list, and Ed Sheeran from my physical booklet of celebrity autographs (a SvenPad). That way the items are being forced from (apparently) real world “things.”

I know that sort of goes against the reason for using DFB in the first place, which is how convenient it is and that it doesn’t require you to carry anything else. But I’m just saying that’s what I’d do if I was intent on doing a double-prediction. Even if you’re forcing from two, organic-seeming, normal notes on your phone, I think doing it twice in the same effect is going to almost always feel like, “the trick with the lists on his phone.” Which is just not ever going to be the most powerful thing you could do with this tool.