[Scid-users] Automated annotations: why/when variations, NAGs?

[Dan F. <dan...@gm...>]

Greetings, SCIDFolk,

When I have Stockfish configured for Analysis, and I perform an automated
annotation, I see variations are introduced in the PGN window, as well as
NAG codes.

On what basis are both of these created? That is:

1. What is "deciding," and on what basis, that it's time to introduce a
variation into the annotation?

2. Some moves get annotated, and some don't. What is "deciding," and on
what basis, that a particular move should be annotated?

3. What is the algorithm for "deciding" which NAG should be used for any
given position? I don't find anything in Stockfish's documentation
indicating that it generates them, so I assume they're coming from SCID.

I looked through the SCID documentation, google, etc. and all I could find
was generic text indicating that NAGs are supported in PGN files, and a
table indicating what the various NAG codes mean. Nothing about the
rationale behind variation or NAG code generation.

I also had a cursory dig through the SCID source code to find where any of
the above take place, and couldn't see anything obvious.

I'm not averse to digging further, if someone could point me in the general
direction of the relevant documentation or source code.

Thanks and regards,

Dan Friedman