I've been reading J. Fairbairn's Evening Fragrance edition... and there are a couple of things that piked my curiosity.
I recall when I first started looking at Go that you could read things about Tengen as a first move. Good / not good, disrespectful... I haven't seen much of that of late, but I was wondering...
If your starting board already has four stones, two each, at hoshi, then Tengen is not that much far away AND it's helping you connect two separate groups AND keeping your opponent's groups separated. Only in taxes, that's four points difference. I have to wonder if the politeness thing about Tengen comes from this, and it simply didn't fall into disuse when the setting changed.
Also, he mentions the quirkyness of giving results as "Color +diff". Again, I'm supposing, BUT. If the results were counted by filling up the spaces alternatively, then the end result would be how many spaces (minus tax) were left when the losing player ran out of space.
Dunno, it's just thinking "aloud", but... Any takers?
Take care.
--
Ferran