Interchangeable ch/sh and k/t characters

[Jorge_Stolfi]

I started simply looking at multiple consecutive repeats and since you mentioned taiin isn’t as popular as kaiin

I have an explanation for that...  but it implies a high rate of errors, which seems to be a unpopular idea among the patrons of this pub.

The non-platform gallows k and t are usually tall, but sometimes they are short, no taller than a d. 

The normal way to write a d would be: write an e, then trace a plume from the top of the e that loops down and closes at the bottom of the e.  But sometimes the plume fails to close, leaving the d open at the bottom.  Sometimes the e comes out straight (j). Sometimes both things happen.

Those variants occur occasionally on the vellum copy.  On the Author's draft, presumably they were more common.  But an open-bottom d is barely different from a short k:

   

So my explanation for the excess of kaiin is that the Author's daiins were often misread by the Scribe as kaiins.  But not as taiin, because the second loop of the later.  The confusion probably happened in other words like chedal <-> chekal, but those do not stand out so much in the statistics because those d-words are nowhere as common as daiin.

All the best, --stolfi