For memorizing long sequences of numbers, names, or cards, advanced learners combine a number-encoding system with the Method of Loci. The Major System, traditionally credited to Stanislaus Mink von Wennsshein in his 1648 Arithmetica Memoriosa (though Pierre Hérigone published a similar Latin version in 1634), maps consonant sounds to digits: 0 = s, z, soft c; 1 = t, d; 2 = n; 3 = m; 4 = r; 5 = l; 6 = sh, ch, j; 7 = k, g; 8 = f, v; 9 = p, b. Vowels and the consonants w, h, and y are silent placeholders, so any number can be padded into a pronounceable word. Only the sounds count, never the spelling, which means consonant clusters normally encode as several digits—"green" is g-r-n = 742, "stone" is s-t-n = 012—except when two letters spell a single sound, as in "ship" (sh = one 6). Context disambiguates letters that can sound like different digits, as with "c" in cent versus cat. The Major System is essentially the same thing as the phonetic number system under a different name.
A worked example for 3.14159 is m-t-r-t-l-p, which reads as "my turtle pie" and becomes a single vivid image at the first locus of a palace. The technique also lends itself to dates: for 1066, the last two digits 66 = j-dg yield "judge," so a learner might picture a judge presiding over the Battle of Hastings. Memorization of pi proceeds by converting successive digit groups to consonants, padding with free vowels into words, and placing the resulting images along a familiar route in order. The Person–Action–Object, or PAO, system extends this idea by assigning each two-digit number from 00 to 99 a unique person, a unique action, and a unique object. Three consecutive two-digit numbers then produce a scene of one person performing one action on one object at a single locus, allowing six digits to be encoded per location.
The Dominic System, devised by memory competitor Dominic O'Brien, is a closely related Person–Action scheme that maps digits to initials—1 = A, 2 = B, 3 = C, and so on—so each two-digit number becomes a famous person's initials paired with a characteristic action, producing 100 person-action pairs. Higher-capacity variants such as Ben Pridmore's Ben System encode three digits at a time (000–999) as a single consonant-vowel-consonant image, roughly tripling the digits stored per locus at the cost of learning 1,000 images; similar variants circulate under various names such as the Master System. For most learners, the standard Major System is the right starting point. Advanced users integrate these tools rather than choosing one. A typical pipeline converts numbers to images via the Major System or PAO, then stores those images at loci in a memory palace, while a Peg System handles shorter ordered lists like shopping items or to-do tasks. The same architecture underwrites memorization of passwords and PINs by converting each character to a peg or keyword image, addresses by walking a familiar route and placing numbers at landmarks, and mathematical formulas by turning symbols into objects—E = mc² becomes Einstein mass squaring off with a candle. Memory athletes train daily with progressive challenges—more decks, longer sequences, faster recall—maintaining multiple pre-built palaces and drilling established systems until visualization is automatic; in the speed-cards event top competitors encode a shuffled 52-card deck in well under 20 seconds, the product of years of practice on fixed images rather than a general visualization rate.