A Card “Force” Using Unintuitive Mathematical Odds

“A card force is one of any number of methods used in close-up magic to apparently offer a subject a free or random choice of card, when in fact the magician knows in advance exactly which card will be chosen. This can then be revealed later in the trick.”

Premise: We have a set of three cards, all of which are known to us. We attempt to force a specific card on the unsuspecting participant by instructing them to randomly point at one of three cards, which are all laying face down. Theoretically, they have a one in three chance of picking the correct card randomly. If they point at the desired card, we immediately instruct them to flip it, effectively “forcing” the card on them in one try. If this works on the first try, the trick will be especially impressive. However, if it doesn’t work on the first try, we still have a fall-back method:

If they point at one of the other cards, instead of telling them to flip the card, we pretend that they’re playing a game of elimination and we simply remove the card, instructing them to point again. If they point at the next incorrect card, we instruct them to remove it, leaving one final card: the correct one.

Potential downside: If they point at the desired card on the second step, then the “force” fails,
because when we remove it, the end card will actually be the incorrect one.

Cards used: Ace of Hearts (the desired card), Queen of Clubs, and 8 of Spades

Approximate Results After 2000 Simulations:
Times ended on Ace of Hearts: 1322 (0.661)
Times ended on Queen of Clubs: 339 (0.1695)
Times ended on 8 of Spades: 339 (0.1695)

Click here to run the simulations yourself using javascript

Odds of picking the right card during the first step: 1/3. If incorrect card is chosen on first step, we pretend it’s an elimination game and remove the card, leaving only two cards, the desired card, and the incorrect card. At this point, you might think there is an even 50/50 chance they will choose the correct card, but in reality, the odds of them choosing and eliminating the desired card are still 1/3 because it hasn’t been touched. The odds of them choosing and eliminating the second incorrect card, however, have increased to 2/3. This is unintuitive, but the simulation shows it to be true.

Because of the fact that we know which cards are which, we can effectively double our seemingly low 33% odds all the way to 66% simply by using this card force method.

The only unsolved problem is, how do you handle a dead end where someone chooses the wrong card, and then the right card on the second step?

Flash 10 Demo

Grant Skinner (gskinner.com) just recently posted this Flash 10 3D music visualizer demo on his “gBlog”. It’s crazy awesome, and even after examining the source code, I’m still not sure how it all works.

For what it’s worth, I went and edited it a bit, removing the music visualizer stuff and just making it spin according to your mouse position over it. Fun stuff. Check it out (P.S. Get Flash 10, Now!):

Hot Air Balloon Ride

This past Saturday, I went on a hot air balloon ride! We went over a mile high, and it was awesome!

My business partner, Chris Tingom, came along (he rode in the other balloon) and he took a video of the experience, and a few photos. I took a video as well, but he beat me to the punch in getting something up online, so I’m just going to show you his stuff for now. At some point, I’ll eventually get mine all edited and up online for viewing, but that could be a while.

Balloon Ride

Balloon Ride

Balloon Ride

Bowling Shoes = Higher Score

Bowling Shoes
Much to the amusement of many of the people I have bowled with, I can’t bowl in a straight line for the life of me. In an attempt to solve the problem I took up experimenting with throwing curve balls, and, after a lot of trial and error, eventually learned how to *occasionally* get the desired effect.

Now, I just want to take a moment to emphasize the fact that I’ve never been a good bowler, probably only bowling a couple of times a year (if that). Even with my best attempts, I have never really averaged more than around 115.

I *do* enjoy bowling, though, so I was pleasantly surprised when my Aunt Pam bought me a pair of bowling shoes as a gift. They are extremely comfortable (maybe even more so than my normal shoes), and fit me perfectly. Bowling shoes usually rent for $3-5, so bowling just got that much more affordable.

Since receiving the shoes, I have gone bowling a couple of times and have been amazed by what a difference they made. Each time I bowled, everything just seemed to click… Literally overnight, my average game went up over 20 points!

At any rate, last week I went bowling with my two buddies, Brian Shaler and John Murch, and I bowled a 201!! Now, I know that a lot of people out there bowl around 200 all the time, but for me that was a big deal (the highest I’ve ever bowled). I even got a print-out of the scores (upon Brian’s recommendation) as proof!

So, yeah. Go get yourself some bowling shoes! 🙂

Litmus Test for Door to Door Sales

If I ever get down on my luck, I’m totally going to start a business selling “No Soliciting” signs from door to door.

The way I see it, it’s practically a guaranteed sale…

“Sorry, we’re not interested in whatever you’re selling! In fact, we hate door to door sales people!”

“Well in that case, you’ll love this sign!”

The best part about it is that if they don’t buy the sign, you can just come back every week until they do. After all, they don’t have a sign saying you can’t!


Man, things have been so crazy busy lately. Everyone wants a piece of the Tornado Design pie, and it’s everything we can do just to stay on top of things.

Just this last Friday, we landed a job with Warner Bros. Records, revamping a multi-media CD for Green Day. The deadline was Tuesday, and we actually managed to meet it (although I had to work practically all weekend). Then, out of the blue, they referred *another* project to us, a multi-media cd for the Gipsy Kings. The deadline for that CD was Wednesday (today), and we managed to meet it, too! So yeah. Things have been pretty crazy lately.

In other news, I re-vamped my living room last week! I got a new entertainment center and a much-needed coffee table that I’ve been wanting for a long time. I’ll have to post some pictures or something.