Australian Dating Service

This is my personal interpretation of Hofzinser’s Royal Marriages card plot. It is very easy to perform and, therefore, well-suited to beginner card magicians. I have also created a presentation inspired by the modern dating scene and the matching algorithms used by online dating sites like Match.com and more recent smartphone apps such as Tinder and OkCupid.

JUMP AHEAD

On This Page

Effect
Background & Credits
Requirements & Preparation
Method & Presentation
Cleanup & Reset
Performance Tips & Additional Ideas
Final Thoughts

Effect

The four Kings and Queens are removed from a deck of playing cards, and the eight cards are thoroughly mixed. A spectator indicates one card, such as the King of Hearts, which is turned face up and placed onto the table. You inform your audience that you are going to use a “matching algorithm”, like the ones used by online dating apps, to find the King his “perfect partner”.

You demonstrate the “Australian Algorithm”: one card is dealt to the table; the next is slid under the packet. You continue eliminating cards using this “down-under deal” until you hold a single card. It is turned over to reveal the Queen of Hearts—a perfect match!

Another card is chosen and matched with the card of the same suit using the same procedure. You explain that the algorithm is one hundred per cent effective; it never fails.

For the finale, a card is chosen, but this time you do not look at its face. You explain that sometimes the app forces you into “Blind Date Mode”, where you must commit to a match before seeing the profile picture. You place the card face down on the table. The card is clearly shown to the audience (e.g., the Queen of Diamonds) as you look away.

You perform the algorithmic elimination procedure again, ending up with the King of Clubs. It appears to be a mistake, as the face-down card (the “date”) is assumed to be the Queen of Diamonds. However, you smile and say, “The Aussie Algo never fails!” You turn over the card on the table to reveal that it has transformed into the Queen of Clubs. A fourth perfect match! The spectator turns over the remaining face-down pair to reveal the Queen of Diamonds paired with the King of Diamonds.

Background & Credits

The precursor to the modern Royal Marriages plot is “The Queen of Hearts” by the famous Viennese magician Johann Nepomuk Hofzinser. It can be found in J.N. Hofzinser’s Card Conjuring by Ottokar Fischer (1931, page 127), translated from the German-language book Kartenkünste, also by Ottokar Fischer.

However, the trick is most often associated with Dai Vernon, thanks to his version in Select Secrets (1941, page 11). There is also evidence that Arthur Finley had a method, and he suggested the plot to Vernon in the 1920s.

The Swindle Shuffle, or “Deal or Switch” mixing procedure, was devised by Paul Curry and first published as part of a trick called “A Swindle of Sorts” in his 1974 book Paul Curry Presents.

Requirements & Preparation

Remove the four Kings and Queens from the deck. Arrange the packet so that the Kings are on top of the Queens (alternatively, the Queens can be on top of the Kings; it doesn't matter). The suit order of the Kings should follow the same order as the suits of the Queens; for example, if the Kings are in Clubs, Hearts, Spades, Diamonds (CHaSeD) order, the Queens must also be in that same order.

I usually put the cards in the following order, looking at the cards face up, from left to right: KC-KH-KS-KD-QC-QH-QS-QD.

This is not the only arrangement that you can use; as long as each matching suit is four cards apart, the trick will work.

Method & Presentation

Begin by displaying the Kings and Queens as you introduce the concept of modern romance:

“Online dating can be a tricky business. It feels like you are constantly shuffling through the same faces, trying to find your perfect match.”

Spread the cards face up between your hands to display them to your audience. Break the spread and push a small group of cards—say one, two or three—from the bottom of the left-hand portion to the top of the right. Then reverse this action: push a few cards from the top of the left-hand portion to the bottom of those held in your right. As you shuffle the cards in this way, say, “You have to sift through hundreds or perhaps even thousands of online profiles before you find ‘The One’!”

Repeat this casual, face-up Charlier Shuffle a few times. With sufficient practice, it looks like a messy, thorough mix, but the packet’s cyclic order remains intact (all the shuffle does is repeatedly cut the cards). Keeping the cards face up when performing a Charlier Shuffle is especially effective because your audience sees a jumble of suits in motion, creating the impression that the cards are being mixed haphazardly. Follow this with another face-down Charlier Shuffle and a few straight cuts.

🔥 Hot Tip: When doing a Charlier shuffle, remember the rule “top to bottom, bottom to top”. The messier the spread, the more convincing the false shuffle!

“But the apps give us choices. We can filter our matches,” you say as you perform the “Deal or Switch” procedure (Paul Curry’s Swindle Shuffle) to ostensibly mix the cards further according to the spectator’s whims. Hold the packet face down. Tell the spectator that you will mix the cards, but they must decide how the algorithm processes them. Ask, “Do we deal or switch?”If they say “deal”, deal the top card onto the table. However, if they say “switch”, take the top two cards, swap their positions, and drop them as a pair onto the table. Repeat this process until you run out of cards. This procedure appears to randomly mix the cards, but it actually only reverses their order. Note: You may repeat this procedure if you so wish; simply pick up the tabled pile and perform another Swindle Shuffle; I think three times in a row is more than enough, though.

Spread the cards evenly between your hands and ask the spectator to touch one. Turn the selection face up (e.g., the King of Diamonds) and cut it to the top of the packet. Deal the King onto the table. “The King of Diamonds is looking for love. Let’s run his profile through the Australian Algorithm.” Perform a Reverse Faro Shuffle: Upjog every second card, strip the upjogged packet out, and place it underneath the other cards. As you do this, you can explain that the algorithm is sorting the data: “He could match here... or here... or here.” Perform the Down-Under Deal (deal one card to the table, slide the next under the packet, then repeat). “The algorithm filters out the incompatibilities... until we have a winner. Down, under, down, under, down, under, down, under, down, under, down...” Reveal the final card is the Queen of Diamonds. A perfect match.

“People say it’s luck, but the ‘Aussie Algo’ is one hundred per cent effective. Satisfaction guaranteed!” Repeat the entire process with the remaining six cards: Perform an Reverse Faro Shuffle. Have a card chosen, turn it face up, and move it to the top. Deal it onto the table (e.g., the Queen of Clubs). Perform another Reverse Faro on the remaining five cards. Perform the Down-Under Deal to reveal its mate (the King of Clubs).

You are now down to four cards. Cut the packet a few times, then have the participant touch the back of any card. Cut this card to the top. As you do so, casually catch a break below the top two cards. “Sometimes, these apps force you into ‘Blind Date Mode’,” you explain. Execute a Double Lift (holding two cards as one) to display the card to your audience—say, the Queen of Hearts—while you look away.

“This is a Blind Date. The profile picture is blurred. You have to commit to the match before you see the person’s face. Scary, huh?!” Turn the double card face down and deal the top card (actually the King of Spades) onto the table. Your audience believes this is the Queen of Hearts.

Perform the final Down-Under Deal with the remaining three cards. You will be left with the Queen of Spades. “The algorithm has paired our mysterious lover with the Queen of Spades.” Pause for effect, then smile. “There’s a famous research paper about the ‘Gale-Shapley’ algorithm used by apps like Hinge. It found something incredible: the algorithm works even when it doesn’t. They discovered a placebo effect. If you believe the maths has found your perfect match, you actually have a better date.” Turn over the card on the table to reveal that it has transformed into the King of Spades. “A perfect match. See? The Australian algorithm never fails!” Have the spectator turn over the last two cards on the table to reveal the final pair (the King and Queen of Hearts), completing the quadruple match-up.

Cleanup & Reset

None required. Simply return the Kings and Queens to the deck.

Performance Tips & Additional Ideas

Most versions of Hofzinser’s Royal Marriages lack a surprising climax. Once the audience sees the first two pairs match, they assume the rest will follow suit, and the theatrical tension quickly evaporates. My solution is to add a surprising, magical moment to the third match-up, which makes the audience eager to see which two cards remain (the “Blind Date” phase). Introducing the face-down card and an apparent mistake breaks the repetitive pattern. The audience is momentarily unsure of the outcome, which makes the final two match-ups a genuine magical surprise rather than a foregone conclusion.

To add intellectual weight to the routine, I’ve referenced the Gale-Shapley algorithm (the Nobel Prize-winning formula used by apps like Hinge) in the suggested script. The associated placebo effect provides a fascinating presentational hook: the magic happens because the spectator trusts the maths, which, weirdly, is true. After all, the trick relies on several mathematical principles to work! (See Finding Love on a First Data: Matching Algorithms in Online Dating for complete details of the study.)

Although this trick isn’t technically demanding, it is important to follow the correct sequence of events. It is very easy to get things wrong and embarrass yourself. For example, if you forget one of the Reverse Faro Shuffles, you’ll be left with mismatched couples.

Final Thoughts

“Aussie Dating Service” is a modernisation of a classic plot that resonates with anyone who has swiped left or right. By wrapping the mathematical principle of Royal Marriages in the relatable context of modern online romance, as well as adding the “Blind Date” kicker, a dry puzzle is transformed into an engaging and playful piece of magic.

The routine creates a high level of audience participation without risking the method, making it an ideal opener for strolling magic or casual performances. Trust the algorithm, remember your reverse-faros, and you will find the perfect match every time.