Bible Code — Equidistant Letter Sequences

In 1994 Israeli mathematicians Doron Witztum, Eliyahu Rips, and Yoav Rosenberg published a paper in Statistical Science claiming to find statistically significant equidistant letter sequences (ELS) in the Hebrew text of Genesis. They claimed that the names of famous medieval rabbis appeared encoded in the text at unusually short skip intervals, clustered near their dates of birth and death.

The paper caused a sensation. In 1997 journalist Michael Drosnin published The Bible Code, extending the method to predict modern events — the assassination of Yitzhak Rabin (cited after the fact), the Gulf War, and others. Drosnin's challenge: "When my critics find a message about the assassination of a prime minister encrypted in Moby-Dick, I'll believe them."

In 1997, mathematician Brendan McKay accepted the challenge. He found messages in the English text of Moby-Dick predicting the assassinations of Indira Gandhi, Yitzhak Rabin, John F. Kennedy, Robert F. Kennedy, Martin Luther King, Abraham Lincoln, and Leon Trotsky — all using Drosnin's exact method. The findings appeared in Statistical Science in 1999, co-authored with Dror Bar-Natan, Maya Bar-Hillel, and Gil Kalai. The original Witztum-Rips experiment was independently shown to depend entirely on a specific controversial list of rabbis; when an independent list was substituted, the effect disappeared entirely.

Take any text. Remove all spaces, punctuation, and numbers, keeping only letters. This gives you a letter string. Now pick a target word and a skip value d. Starting at position p, read every d-th letter: positions p, p+d, p+2d, and so on. If the result spells your target word, you have found an ELS at (start=p, skip=d).

Text = ABCDEFGHI, target = ADG
Zero-based start 0, positive skip 3: positions 0, 3, 6.

For length N, target length m, and positive skips 1…D:
valid start/skip pairs = Σ max(N − (m−1)d, 0).

N = 100,000, m = 4, D = 1,000:
98,498,500 valid pairs (not 100,000,000).
Under independent uniformly distributed A–Z letters,
expected hits = 98,498,500 / 26⁴ ≈ 215.54.

The expectation above uses an independent uniform-letter model, not real prose. With independently sampled nonuniform letters, multiply the number of valid pairs by the product of the target letters’ probabilities. Overlapping searches need not be independent for this expectation, but a significance test needs an appropriate distribution and must account for other searched words and settings.

The boxes compare a prose passage with a shuffled control containing the same letters. Their hit counts may differ. This comparison is an illustration, not a significance test or proof that the texts are statistically indistinguishable. A sound test needs a specified hypothesis, null model, search procedure, and accounting for all comparisons.

Try target words: EDEN, DEATH, WAR, KING, ASSASSIN. The hit count tracks nothing but word length and letter frequency: short common-letter words turn up again and again, longer ones never appear at all — and the random control behaves the same way. The "Bible Code" method gives you no way to distinguish these hits from noise.

• Voynich Manuscript — genuinely unsolved; statistical analysis has proved its letter distributions are unlike any known cipher or natural language
• Beale Ciphers — another case where "finding" a partial decode via book cipher may be pattern-matching rather than cryptanalysis
• Kryptos — four panels, three solved; the fourth is a genuine open problem, not a statistical artefact
• Caesar Cipher — chi-squared scoring is the correct way to distinguish signal from noise in a short substitution cipher