The oddities of the bigram "ed"

[Dunsel]

If VMS was a cipher and different cipher tables (keys, mappings) were used for different folios, this behavior of ed would be easy to explain. Say, for some folios ed maps to plaintext ST, for other folios ed maps to plaintext GP, very different statistics. However, even under this scenario it's hard to explain why it's only ed that behaves like this.

Is it possible to probe trigrams/tetragrams and see whether any particular longer ngram that contains ed causes this effect?

Excellent question.  You'd think that if ed exhibits that behavior then edy, would also.  But, it doesn't. It's the one on the top right of the chart.  It does only occur on half the pages so as a trigram across the entire Voynich, anything with ed will stand out.  But, within the pages with ed it still follows the curve.   If it were on just half of the pages with ed, which would be hard to do, then it would stand out.

   

So maybe a tetragram containing ed?  Nope.  Same problem as above.

   

The bigram ed is in a class all by itself.