Contextual Compression with "7za"

This is the result of taking the first 50k of 11 different randomly-selected texts and "7za"-context-compressing them against each other, in pairs, to see which will compress together the best. (The files used are streamlined versions of texts from Project Gutenberg.) The texts used:

• The Aeneid, by Virgil (English translation)
• On the Duty of Civil Disobedience, by Henry David Thoreau (English)
• Manifesto of the Communist Party, by Karl Marx (English translation)
• The Picture of Dorian Gray, by Oscar Wilde (English)
• An Essay on Man: Moral essays and satires, by Alexander Pope (English)
• Evangeline: A Tale of Acadie, by Henry Wadsworth Longfellow (English)
• The Tragedie of Hamlet, by William Shakespeare (English)
• Huckleberry Finn, by Mark Twain (English)
• La Divina Commedia, by Dante Alighieri (Italian)
• The Soul of Man, by Oscar Wilde (English)
• The Tao Te Ching, by Lao Tzu (English translation)

Clearly, the algorithm can best compress a file that is paired with another copy of itself...

17304: Communist_Manifesto.txt(50k) -7za- Communist_Manifesto.txt(50k)
18321: Soul_of_Man.txt(50k) -7za- Soul_of_Man.txt(50k)
18554: Tao_Te_Ching.txt(50k) -7za- Tao_Te_Ching.txt(50k)
18771: Huckleberry_Finn.txt(50k) -7za- Huckleberry_Finn.txt(50k)
19286: Dorian_Gray.txt(50k) -7za- Dorian_Gray.txt(50k)
19493: Evangeline.txt(50k) -7za- Evangeline.txt(50k)
19662: Civil_Disobedience.txt(50k) -7za- Civil_Disobedience.txt(50k)
19908: La_Divina_Commedia.txt(50k) -7za- La_Divina_Commedia.txt(50k)
20557: Essay_on_Man.txt(50k) -7za- Essay_on_Man.txt(50k)
20597: Hamlet.txt(50k) -7za- Hamlet.txt(50k)
20598: Aeneid.txt(50k) -7za- Aeneid.txt(50k)

..This illustrates that the [English translation of] The Aeneid is the most difficult for 7za to compress of the texts, while the Communist Manifesto is the easist.

..but, as the results continue, we can see the cross-combination benefits of the different texts:

33879: Communist_Manifesto.txt(50k) -7za- Soul_of_Man.txt(50k)
33913: Soul_of_Man.txt(50k) -7za- Communist_Manifesto.txt(50k)
34427: Communist_Manifesto.txt(50k) -7za- Tao_Te_Ching.txt(50k)
34440: Tao_Te_Ching.txt(50k) -7za- Communist_Manifesto.txt(50k)
34981: Communist_Manifesto.txt(50k) -7za- Huckleberry_Finn.txt(50k)
34985: Huckleberry_Finn.txt(50k) -7za- Communist_Manifesto.txt(50k)
35117: Communist_Manifesto.txt(50k) -7za- Dorian_Gray.txt(50k)
35165: Dorian_Gray.txt(50k) -7za- Communist_Manifesto.txt(50k)
35248: Tao_Te_Ching.txt(50k) -7za- Soul_of_Man.txt(50k)
35271: Communist_Manifesto.txt(50k) -7za- Civil_Disobedience.txt(50k)
35299: Soul_of_Man.txt(50k) -7za- Tao_Te_Ching.txt(50k)
35301: Civil_Disobedience.txt(50k) -7za- Communist_Manifesto.txt(50k)
35630: Evangeline.txt(50k) -7za- Communist_Manifesto.txt(50k)
35657: Soul_of_Man.txt(50k) -7za- Dorian_Gray.txt(50k)
35667: Communist_Manifesto.txt(50k) -7za- Evangeline.txt(50k)
35707: Dorian_Gray.txt(50k) -7za- Soul_of_Man.txt(50k)
35806: Huckleberry_Finn.txt(50k) -7za- Soul_of_Man.txt(50k)
35830: Soul_of_Man.txt(50k) -7za- Huckleberry_Finn.txt(50k)
36050: Soul_of_Man.txt(50k) -7za- Civil_Disobedience.txt(50k)
36065: Civil_Disobedience.txt(50k) -7za- Soul_of_Man.txt(50k)
36154: Tao_Te_Ching.txt(50k) -7za- Huckleberry_Finn.txt(50k)
36216: Huckleberry_Finn.txt(50k) -7za- Tao_Te_Ching.txt(50k)
36378: Tao_Te_Ching.txt(50k) -7za- Dorian_Gray.txt(50k)
36392: Dorian_Gray.txt(50k) -7za- Tao_Te_Ching.txt(50k)
36471: Essay_on_Man.txt(50k) -7za- Communist_Manifesto.txt(50k)
36510: Communist_Manifesto.txt(50k) -7za- Essay_on_Man.txt(50k)
36533: Huckleberry_Finn.txt(50k) -7za- Dorian_Gray.txt(50k)
36536: Dorian_Gray.txt(50k) -7za- Huckleberry_Finn.txt(50k)
36559: Tao_Te_Ching.txt(50k) -7za- Civil_Disobedience.txt(50k)
36566: Civil_Disobedience.txt(50k) -7za- Tao_Te_Ching.txt(50k)
36595: Soul_of_Man.txt(50k) -7za- Evangeline.txt(50k)
36623: Evangeline.txt(50k) -7za- Soul_of_Man.txt(50k)
36669: La_Divina_Commedia.txt(50k) -7za- Communist_Manifesto.txt(50k)
36672: Communist_Manifesto.txt(50k) -7za- La_Divina_Commedia.txt(50k)
36748: Evangeline.txt(50k) -7za- Tao_Te_Ching.txt(50k)
36782: Tao_Te_Ching.txt(50k) -7za- Evangeline.txt(50k)
36823: Aeneid.txt(50k) -7za- Communist_Manifesto.txt(50k)
36837: Communist_Manifesto.txt(50k) -7za- Aeneid.txt(50k)
36869: Communist_Manifesto.txt(50k) -7za- Hamlet.txt(50k)
36897: Hamlet.txt(50k) -7za- Communist_Manifesto.txt(50k)
36991: Civil_Disobedience.txt(50k) -7za- Huckleberry_Finn.txt(50k)
37013: Huckleberry_Finn.txt(50k) -7za- Civil_Disobedience.txt(50k)
37098: Evangeline.txt(50k) -7za- Huckleberry_Finn.txt(50k)
37143: Huckleberry_Finn.txt(50k) -7za- Evangeline.txt(50k)
37204: Civil_Disobedience.txt(50k) -7za- Dorian_Gray.txt(50k)
37225: Dorian_Gray.txt(50k) -7za- Civil_Disobedience.txt(50k)
37306: Essay_on_Man.txt(50k) -7za- Soul_of_Man.txt(50k)
37329: Evangeline.txt(50k) -7za- Dorian_Gray.txt(50k)
37339: Soul_of_Man.txt(50k) -7za- Essay_on_Man.txt(50k)
37369: Dorian_Gray.txt(50k) -7za- Evangeline.txt(50k)
37635: Essay_on_Man.txt(50k) -7za- Tao_Te_Ching.txt(50k)
37677: Tao_Te_Ching.txt(50k) -7za- Essay_on_Man.txt(50k)
37691: Soul_of_Man.txt(50k) -7za- La_Divina_Commedia.txt(50k)
37706: La_Divina_Commedia.txt(50k) -7za- Soul_of_Man.txt(50k)
37718: Soul_of_Man.txt(50k) -7za- Hamlet.txt(50k)
37773: Aeneid.txt(50k) -7za- Soul_of_Man.txt(50k)
37774: Soul_of_Man.txt(50k) -7za- Aeneid.txt(50k)
37783: Evangeline.txt(50k) -7za- Civil_Disobedience.txt(50k)
37794: Civil_Disobedience.txt(50k) -7za- Evangeline.txt(50k)
37825: Hamlet.txt(50k) -7za- Soul_of_Man.txt(50k)
37939: Tao_Te_Ching.txt(50k) -7za- La_Divina_Commedia.txt(50k)
37948: La_Divina_Commedia.txt(50k) -7za- Tao_Te_Ching.txt(50k)
37981: Tao_Te_Ching.txt(50k) -7za- Hamlet.txt(50k)
38004: Tao_Te_Ching.txt(50k) -7za- Aeneid.txt(50k)
38005: Aeneid.txt(50k) -7za- Tao_Te_Ching.txt(50k)
38046: Hamlet.txt(50k) -7za- Tao_Te_Ching.txt(50k)
38167: Essay_on_Man.txt(50k) -7za- Huckleberry_Finn.txt(50k)
38169: Huckleberry_Finn.txt(50k) -7za- La_Divina_Commedia.txt(50k)
38171: La_Divina_Commedia.txt(50k) -7za- Huckleberry_Finn.txt(50k)
38217: Huckleberry_Finn.txt(50k) -7za- Essay_on_Man.txt(50k)
38307: Huckleberry_Finn.txt(50k) -7za- Hamlet.txt(50k)
38316: Aeneid.txt(50k) -7za- Huckleberry_Finn.txt(50k)
38331: Essay_on_Man.txt(50k) -7za- Dorian_Gray.txt(50k)
38341: Hamlet.txt(50k) -7za- Huckleberry_Finn.txt(50k)
38344: Huckleberry_Finn.txt(50k) -7za- Aeneid.txt(50k)
38371: Dorian_Gray.txt(50k) -7za- Essay_on_Man.txt(50k)
38572: Evangeline.txt(50k) -7za- Aeneid.txt(50k)
38606: Aeneid.txt(50k) -7za- Evangeline.txt(50k)
38614: Aeneid.txt(50k) -7za- Dorian_Gray.txt(50k)
38630: Dorian_Gray.txt(50k) -7za- Hamlet.txt(50k)
38637: Dorian_Gray.txt(50k) -7za- Aeneid.txt(50k)
38647: La_Divina_Commedia.txt(50k) -7za- Dorian_Gray.txt(50k)
38661: Essay_on_Man.txt(50k) -7za- Civil_Disobedience.txt(50k)
38662: Dorian_Gray.txt(50k) -7za- La_Divina_Commedia.txt(50k)
38670: Civil_Disobedience.txt(50k) -7za- Essay_on_Man.txt(50k)
38694: Hamlet.txt(50k) -7za- Dorian_Gray.txt(50k)
38720: Essay_on_Man.txt(50k) -7za- Evangeline.txt(50k)
38781: Evangeline.txt(50k) -7za- Essay_on_Man.txt(50k)
38860: La_Divina_Commedia.txt(50k) -7za- Evangeline.txt(50k)
38871: Evangeline.txt(50k) -7za- La_Divina_Commedia.txt(50k)
38891: Evangeline.txt(50k) -7za- Hamlet.txt(50k)
38943: Hamlet.txt(50k) -7za- Evangeline.txt(50k)
38985: Civil_Disobedience.txt(50k) -7za- Hamlet.txt(50k)
39020: Civil_Disobedience.txt(50k) -7za- Aeneid.txt(50k)
39029: La_Divina_Commedia.txt(50k) -7za- Civil_Disobedience.txt(50k)
39035: Civil_Disobedience.txt(50k) -7za- La_Divina_Commedia.txt(50k)
39037: Aeneid.txt(50k) -7za- Civil_Disobedience.txt(50k)
39041: Hamlet.txt(50k) -7za- Civil_Disobedience.txt(50k)
39725: Essay_on_Man.txt(50k) -7za- Aeneid.txt(50k)
39830: Aeneid.txt(50k) -7za- Essay_on_Man.txt(50k)
39852: Aeneid.txt(50k) -7za- Hamlet.txt(50k)
39905: Essay_on_Man.txt(50k) -7za- La_Divina_Commedia.txt(50k)
39946: Essay_on_Man.txt(50k) -7za- Hamlet.txt(50k)
39951: La_Divina_Commedia.txt(50k) -7za- Essay_on_Man.txt(50k)
39968: Aeneid.txt(50k) -7za- La_Divina_Commedia.txt(50k)
39970: La_Divina_Commedia.txt(50k) -7za- Hamlet.txt(50k)
39975: Hamlet.txt(50k) -7za- La_Divina_Commedia.txt(50k)
39976: La_Divina_Commedia.txt(50k) -7za- Aeneid.txt(50k)
39987: Hamlet.txt(50k) -7za- Aeneid.txt(50k)
40055: Hamlet.txt(50k) -7za- Essay_on_Man.txt(50k)

..indicating that Oscar Wilde's "The Soul of Man" and Marx's "Communist Manifesto" make the best pairing for contextual compression, of the selected texts, and Shakespeare's "Hamlet" and Wilde's "The Soul of Man" make the worst (even worse than pairings with the Italian text of La Divina Commedia).