I agree I made it complicated - I mean he is very nice and very clever

Is there not also the possibility where the baseline of <X> is rather low, thus allowing for a comparatively "highest ratio" of <X> to <Y> without implying a low <Y>?

Not saying that's necessarily the case here, I don't follow the blog either, just pointing out another interpretation.

Right, the parent probably meant lowest ratio. Though that sounds weird in casual conversation.

Except that also occurs when both things are very low - not a compliment either.

Best to steer clear of 'ratio' if praising two traits, sum them or something, don't divide by one of them.

I think the point of the comment was to praise them for how they manage to have equal amounts of both things, when those things are rarely seen together. Most people would assume from context (given that the comment is phrased with positive sentiment) that it was meant that the ratio was low and the implicit sum was high.

Can you give a couple of intuitive examples of "highest ratio of <X> to <Y>"?

High ratio of salary to mundane work - either the work is interesting, or salary is large enough to compensate.

been on both sides of that one. :)