Shadow System

The following text was written by Lance and placed here on

Hi, my name is Lance Tschirhart. I’m the American competitor who placed 11th in the 2013 USA Memory Championship.

The following is a 2-card system I designed and honed over the past couple of months. Many people are intrigued by the idea of building a 2-card system, but few actually complete the task. The Shadow System was created with the sole purpose in mind of being as easy as possible to fill out. Very special Thanks go to Ben Pridmore, Johannes Mallow, and the creator of the Major System for introducing the concepts central to the system.

Let’s begin by comparing the merits and potential disadvantages of these two systems.

Ben System


First consonant

club/club – k
club/diamond – t
club/heart – n
club/spade – m
diamond/club – r
diamond/diamond – d
diamond/heart – l
diamond/spade – g/j
heart/club – f/th

heart/diamond – b
heart/heart – h
heart/spade – p
spade/club – sk/sn/sm
spade/diamond – st/sp
spade/heart – sh/sl/sw

spade/spade – s


A = ‘a’ as in ‘cat’
2 = ‘e’ as in ‘pet’
3 = ‘i’ as in ‘kitten’
4 = ‘o’ as in ‘tom’
5 = ‘u’ as in ‘puss’
6 = ‘A’ as in ‘hay’
7 = ‘E’ as in ‘bee’
8 = ‘I’ as in ‘high’
9 = ‘O’ as in ‘low’
10 = ‘oo’ as in ‘you’
J = ‘ow’ as in ‘cow’
Q = ‘or’ as in ‘oor’
K = ‘ar’ as in ‘car’

Second consonant
A = t
2 = n
3 = m
4 = r
5 = l
6 = g
7 = k
8 = f/th
9 = b
10 = s
J = j/sh/ch
Q = p
K = d

This was almost certainly the first 2-card system invented. It cleanly translates 1000 images that can be represented by all of the digit combinations from 000-999, as well as 1024 images that can be listed as each of the 10-digit binary combinations from 0000000000-1111111111.

The Ben System is an extended major system that serves as an algorithm for producing phonemes. I believe single syllables are important for quick memorization because reducing subvocalization is difficult, and eliminating it is impossible. Most of the phonemes produced by the system are not actual words, and in some cases, the phonemes produced do not exist in any form in English. Even if the consonant and vowel sounds were altered to reflect those commonly used in any other language, this would still be the case – there are just too many combinations.

Some consequences of this setup are:

1) As soon as the system itself is learned, each of the 2704 card combinations can be pronounced with little ambiguity. However, there are exceptions in the five of the sixteen possible suit combinations that are italicized above. This also is a problem with the Major System, and thus, the Shadow System.

2) The phonemes that actually produce words on their own can be restrictive. For instance, when the words “Foot,” or “Feet” occur, it can be difficult to imagine anything else while reading them. On the other hand, it is a breath of fresh air to have words simply handed to you. This is a matter of preference.

3) Since they do not usually make words on their own, the phonemes will usually serve as reminders of the chosen images. As a result, it can be difficult at times to avoid pronouncing the images themselves, which are longer than a single syllable.

4) Each image is distinctly its own. That means that there is little chance of making errors of momentarily lapsed cognition when reconstructing the deck. This may sound like an obvious consequence of a two card system, but mistakes in reconstruction is a potential problem with the Shadow System, though I have not yet experienced it myself after becoming more familiar with the images.

5) It is simple. There is much to be said for this – it’s a very elegant system with perfectly consistent grammar. I am of the opinion that a system with more complex grammar may be preferable, so long as it is easy to fill out. This is a matter of taste.

Remember that the Ben System is tried and true: it has been used to set world records in various events and is a favorite of top competitors.

The Shadow System (SS)

SS uses the Major System:


SS is based on the assumption that it is easier to remember semantically related word pairs than words that are created based on phonetic cues, and that this is especially true when you create the word pairs yourself. Also, that it is easier to remember words that have been chosen with less phonetic restrictions. Finally, as opined above, that it is preferable (easier) to learn a new system of grammar than to fill out a system with nonsense syllables.

A member of these forums told me that after using the Ben System for six months, he had achieved a personal best of 44 seconds for memorizing a deck. He said that he felt he could improve much more, but the only problem was how difficult it was to decode the 16 suit combinations on the spot. Granted, this would become natural given enough practice. Still, this hurdle was the first to be eliminated. By pairing each suit combination with another, SS uses different phonetics for only 8 suit combinations. Thus, a greater variety of different sounds can be packed within each number 0-9, or with cards, 10-9, with the original Major System. All numbers in SS adhere to the Major System strictly. The first 4 suit combinations are as follows:

Initial consonants:

#♠#♠ – S,Z
#♥#♥ – S,Z
#♠#♥ – T,D
#♥#♠ – T,D
#♣#♣ – K,G
#♦#♦ – K,G
#♣#♦ – P
#♦#♣ – P

These initial consonants are represented by the suit combinations. Notice that for the Suits that are the same color, namely ♠♠, ♥♥, ♣♣, ♦♦, The Clubs’ sound is paired with the Diamonds’, and the Spades’ with the Hearts’.
These are not assigned as arbitrarily as it may appear at first. Because it takes so long to become familiar with such a large list, SS is built to facilitate as much training as possible before the list is complete. “#♠#♠,” “S,” is the easiest to fill out, followed by “#♣#♣,” (K,G) “#♠#♥,” (T,D) and “#♣#♦” – (P). In the Major System, these are represented in digit form by all numbers 000-199, 900-999, and 700-799. As the 000-999 list begins to be filled out, one can begin to train with a deck made of all of the # cards (A-10), for Spades and Hearts, and a similar deck with Clubs and Diamonds. This is a good starting point because in each of these two decks, there are only 200 images represented by the cards, while in a similar deck comprised of, for instance, Spades and Diamonds, there would be 300 images to keep track of: #♦#♦, #♠#♠, and #♠#♦.

The next four suit combinations, which are more difficult to fill out than the first four, are 200-299 (N), 500-599 (L), 600-699 (J,SH,CH) and 300-399 (M). These are to be assigned arbitrarily according to your taste. Mine are assigned based on the level of difficulty I had in filling them out, and the stage at which they would be added into my practice decks. Since (J,SH,CH) and (N) were the most difficult for me, they were assigned to the combinations that would show up only when all of the cards, A-10 of every suit, were put together.

#♣#♥ – L
#♥#♣ – L
#♠#♦ – M
#♦#♠- M
#♠#♣ – J,SH,CH
#♥#♦- J,SH,CH
#♣#♠ – N
#♦#♥ – N

Notice that there are 10 groups of consonants in the major system, and only 8 suit combinations. In total, SS Only translates 992 of the 1000 digit images, excluding 444, 448, 484, 488, 844, 848, 884, and 888.
Two of the most difficult groups to fill out are 800-899 (F,TH), and 400-499 (R). Other groups may be equally difficult, but there is good reason to use these two particular groups as exceptions. Since there is no room for their initial sounds to be represented by suit combinations, there are special rules to accommodate these images.

In order to translate the remaining 200 images into the system, there must be instances in which the suit combinations do not form the initial consonant sounds. This inequality also carries over into the “tens” place, though that may be less intuitive. Thus, face cards, when placed in either the first or both the first and second places, must take precedence over the suit combination preceding it. Since there are only two missing groups, the Jacks and Queens and used for this purpose, while the Kings retain a different set of rules. Queens Always make the sound “R,” and Jacks, when in the first place, make the sounds “F,Th.” However, when Jacks are in the second place, they make the sound “T,D.” We are free to make these kinds of changes because images in which a face card appears in the second place only are among the 352 images that are not in the 000-999 list. “T,D,” as an ending, is preferable to “F,Th,” because there are a paucity of words that end in “F” or “Th.” Because it can include past-tense verbs ending in “ed,” the “T,D” ending is preferable to all others except for “R” and “S.” “S” is only common at the end of words for plurality though, and “R” is already occupied by the Queens. Queens always retain the “R” sound because many professions, appliances, and gadgets end with the letter “R.” When both cards shown are Either JxJx, JxQx, QxQx, or QxJx, the rule of precedence continues to apply, for these combinations match up with the numbers:

QxQx: 440,441,442,443,444,445,446,447,448,449

QxJx: 480,481,482,483,484,485,486,487,488,489

JxQx: 840,841,842,843,844,845,846,847,848,849

JxJx: 880,881,882,883,884,885,886,887,888,889.

The eight numbers that are stricken out are the only eight from the 000-999 list that will not translate into card combinations. The first two digits are dictated by the face cards themselves, out of their precedence, so the digit in the “ones” place is determined by the suit combination.

For instance, “J♠Q♠” may be “forest,” and “Q♠J♥” may be “raft.”

When a face card is in the second place only, an “S” is added in before the suit combination. If it were not, then you would be required to create multiple images with the same phonetic code, which is difficult. For example, “3♣4♥” might be “Lemur,” but “3♣Q♥” would also have to use “L+M+R,” which as you can see, could be difficult. By adding an “S” in front, many new combinations are opened up. “3♣Q♥” Could be “Slimer” or “Slammer.” Thus, it is important that there be a vowel between the “S” and the second consonant in each of your 000-099 images. The words where the two consonants are contiguous should be saved for the situations in which a Jack or Queen appears in the second place.

There will be only ten words for each of the suit combinations in which the second card is a face card, per individual face card. Thus, for “#♠J♥,” there will be ten words that begin with “St,” have a second consonant determined by the first card, and end in “T,D.” For #♠Q♥, there will be ten more that begin with “St,” have a second consonant determined by the first card, and end in “R”. For Kings, new rules apply.

Each of the 8 suit combinations are amenable to having an “S” precede them. The only two consonants of the Major System that are not are “R” and “F,TH.” That is why these are the two groups that are excluded, hence, the initial sounds for instances in which Jack or Queen appears in the second position only are:

#♠J/Q♠ = “S”
#♥J/Q♥ = “S”

#♠J/Q♥ = “St”
#♥J/Q♠ = “St”

#♣J/Q♠ = “Sn”
#♦J/Q♥ = “Sn”

#♠J/Q♦ = “Sm”
#♦J/Q♠ = “Sm”

400-499 = “Sr”

#♣J/Q♥ = “Sl”
#♥J/Q♣ = “Sl”

#♠J/Q♣ = “J,Sh,Ch”
#♥J/Q♦ = “J,Sh,Ch”

#♣J/Q♣ = “Sk”
#♦J/Q♦= “Sk”

800-899 = “Sf”

#♣J/Q♦ = “Sp”
#♦J/Q♣ = “Sp”

Please let me know if you need more examples or further clarification. :)


When a King is in the First position, It takes precedence over the suit combination and is pronounced “H.” When a King is in the second position, it is silent, regardless of what the first card is. That means that all combinations XxKx are single syllable words, and as always, face cards take precedence when applicable.

For example:

“K♣Q♦” may be “Harp”
“Q♣K♦” may be “Rope”
“9♠K♦” may be “Mop”
“K♠5♥” may be “Huddle”

There are 8 instances in which both cards are kings. These could, for the perfectionist, represent 444,448,484,488,844,848,884,and 888. What I do instead is make up a cool image for the doubles (“K♣K♣” is “King Kong”), and retain the “H” sound and grant (only for these four remaining combinations) total precedence to the Kings for the others (“K♠K♥” is “Hi-Hat”).

Part II: Abbreviations and Shadows

This is where SS is really special: If you’ve made it this far, your aren’t just “half way there.” You are actually on the final stretch of having a complete 2704 system.

Up to this point, you could have made a list of 1352 images which can be used in a 2-block system like Johannes Mallow does, in which card pairs beginning with a red card are placed in a loci until a pair beginning with a black card comes up. Its image is placed in the loci alongside the others, and then the next loci is moved to until another card pair beginning with a black card is reached, ad infinitum. This always leaves a degree of uncertainty in how many images will be in each loci, which will vary from deck to deck, and is a bit more difficult for that reason. Still, it’s a fun method that you may prefer to use. The biggest drawback is that at this point is that you only have a list for binary that covers 9 digits at a time.

As the images are created, make a single syllable abbreviation for each object that is unique. Usually, it is the first syllable. Sometimes, you have to make an exception. Only read the objects using these syllables, (never vocalize or subvocalize the entire word), and they should become natural enough in time. This is a necessary step in order to fill out the second half of the list, so do it along the way. If you make the syllables carefully for each group of 100, you can fill out this entire system of 2704 with only a handful of exceptions along the way.

To finish the second half of the system, simply come up with a list of Shadow Images – images that are related to your first in a memorable way. For me, 141, or 4♠A♥, is “Dart.” “4♥A♠” is therefore “Dartboard.” “J♠Q♥” is “Fred” (Fred Flintstone), so “J♥Q♠” is “Wilma.”

Notice that “Wilma” does not follow the phonetic code dictated by “J♥Q♠.” Using the single syllable “Wilm” will be hard to learn to do naturally, because the cards just don’t spell it. Thus, each of the shadow syllables are taken by converting the original syllables in a consistent and systematic way. Each of the shadow syllables uses the same vowel as the original image, but pronounces it in a way that is different from the first syllable. For example,
“J♥Q♠” may mean “Wilma,” but it is pronounced “FrEd,” or “Freed.” For “ir,” “or,” sounds and the like, “ar” is converted to “air” “er/ir” is converted to “or,” and “ur,” which is pronounced the same as “er/ir” but spelled with a “u” is converted to “Ur,” as in a sloppy pronunciation “Sewer.” In all other situations, just pronounce the short/long variation of the same consonant for the syllable.

To make this clear, here is my list of 700-749 objects alongside their shadows. You will see that most of the “exceptions” were not necessary at all. They were just put there to experiment, or to remember neat instances of coincidence. For instance, when “7♣7♣ = Casp (Casper),” the first shadow that came to my mind was “ghostbusters.” Instead of using “CAsp” = Ghostbusters as per the system’s rules, I used “GOsb.” I’ll tell you now it isn’t easier that way, and isn’t even a good idea for a reason I’ll explain below. These were just my first 50 to convert.

700 CAs (Briefcase) 10♦10♦ Cas (Cuffs)
701 cast (cast) 10♦A♦ CAst (CastTakesBow)
702 cus (casino=roulette) 10♦2♦ CUs (Plenko)
703 gas (gasmask) 10♦3♦ GAs (ScubaHelm)
704 gIz (geyser) 10♦4♦ Giz (Volcano)
705 Sul (Castle) 10♦5♦ SUl (Oubliette)
706 gach (gaschamber) 10♦6♦ GAch (Furnace)
707 Gask (Gasket) 10♦7♦ GAsk (Wrench)
708 Kis (Kissyfist) 10♦8♦ KIs (MasterHand)
709 casp (casper) 10♦9♦! GOsb (Ghostbusters)
710 kIt (Kite) A♦10♦ kit (Boxkite)
711 Kid (Katydid) A♦A♦ KId (Mantis)
712 cotn (cotton) A♦2♦ COtn (CottonCandy)
713 cut (cutman) A♦3♦ CUt (Megaman)
714 gAt (gator) A♦4♦ Gat (CrocHunter)
715 cuf (cuttlefish) A♦5♦ CUf (OctopusRide)
716 kij (cottagecheese) A♦6♦ KIj (fruitcup)
717 Kak (Catacomb) A♦7♦ CAk (WeddingCake)
718 caf (catfish) A♦8♦! Cat (cat)
719 cult (catapult) A♦9♦ CUlt (Trebuchet)
720 gun (gun) 2♦10♦ GUn (Gunslinger)
721 cand (candle) 2♦A♦ CAnd (RomanCandle)
722 can (Cannon) 2♦2♦ CAn (Doomcannon)
723 Gan (Ganewmede) 2♦3♦ GAn (Scorpion)
724 Grak (Gunrack) 2♦4♦ GrAk (SwordRack)
725 Cun (Canole) 2♦5♦! Kenl (Kennel)
726 Gonj (PottedGanja) 2♦6♦ GOnj (BigPurpleNug)
727! Gong (Gong) 2♦7♦ Conk (ConchShell)
728 conv (converseFloat) 2♦8♦ COnv (RedConsMoonwalk)
729 gub (gunblade) 2♦9♦ GUb (Firebomb)
730 cam (camera) 3♦10♦ CAm (Flashbulb)
731 com (meteor) 3♦A♦ COm (comb)
732! kO (Kimono) 3♦2♦ GE (Gi)
733 Cum (Chamomille) 3♦3♦ cUm (cumin)
734 kIm (Chimera) 3♦4♦ Kim (Seymour)
735 cul (camel) 3♦5♦! KEl (Chameleon)
736 Guj (Gumdrop) 3♦6♦ GUj (Icing)
737! cank (Camcorder) 3♦7♦! komk (Kamikaze)
738 Camf (Camouflage) 3♦8♦ CAmf (PolkadotSuit)
739 gumb (Gumby) 3♦9♦ GUmb (Goomba)
740! corp (Corpse) 4♦10♦! Cors (Corset)
741 cart (Golfcart) 4♦A♦ CArt (Sandtrap)
742 corn (CandyCorn) 4♦2♦! Grin (Grinch)
743 Krum (Krum) 4♦3♦ KrUm (Lydia)
750 gold (GoldBars) 5♦10♦ Gud (GoldGutter)
744 Cor (AppleCore) 4♦4♦! Cort (AppleCorer)
745 Gril (BlackGrill) 4♦5♦ GrEl (TheBigGreenEgg)
746 CArj (Carriage) 4♦6♦! GArj (Garage)
747 Crik (Cricket=Sport) 4♦7♦ CrIk (BagofCrickets)
748 corv (Corvette) 4♦8♦! Curv (StartingFlag)
749 crip (cripple) 4♦9♦ CRIp (CripWalk)

Hopefully that’s clear.

Other than the easy of being able to pronounce each shadow immediately, there is an even bigger advantage to the SS’ handling of shadow syllables: The syllables do not resemble the words they represent.

This may sound like a disadvantage, but it is not! There is no need for them to resemble the words, since you know what the words are already, and the fact that they do not resemble the words means that there is no temptation – no possibility even – of you attempting to subvocalize any word that is longer than 1 syllable. In the long run, this is going to a be a huge time-saver.

I’ll wrap this up by explaining the binary aspect.


The 1000 list covers the 512 9-digit binary combinations in the form 010.110.101 = 2.6.5
To make this compatible for 10-digit binary images, use the form:

(0)010110101 = 265
(ex.) Anj = Angel

(1)010110101 = 265 [shadow] (ex.) anj = Demon

That’s the whole thing. Let me know your thoughts or if you have any questions.

Shadow System