These last days, I've been trying to understand the meaning of the "Sho" versions of the katas. Personnaly (Shotokan) I just know Kanku and Bassai-Sho (not yet Gojushiho), but it is really not clear for me what are these katas for, and where they are coming from.
Finally who created these katas and for which purpose ? I would be keen to think it's Itosu who created them, at least Kanku Sho, and for one simple reason: The morote Uke ! Indeed, you retrieve morete uke (a lot) in the Heian / Pinan, and then ...? Beside in Kanku Sho this is not much to be found in any other kata isn't it ...??
And I heard an explanation of them being: they would record these elements that are found in the "Dai" versions but that are not overlapping with other katas of the curriculum... My problem with that explanation is that I retrieve in both Kanku and Bassai-Sho lots of movements not found in the Dai versions.
So, could it be that these katas are in fact a kind of "master class" of the dai versions, created by Itosu, in order to record more complex principles and flows on basis of the dai versions, principles and flows that Itosu created himself ???