I don't understand the "new" settings for warp density (I don't know when they changed, but tedit mentions that they did.)

The default is 30% two-ways. So if you have 1000 sectors, it initially creates only 300 two-way warps. Since both have two ends, that's 600 outbound warps -- not even one for every sector. Why so few? Do the majority of warps come from linking inaccessible clusters?

As far as I know, this hasn't changed at least late TW v2.

Bigbang generates the specified percentage of 2-ways, then the specified percentage of 1-ways, then goes through all sectors and for any orphaned sector it finds, links it into the main map with a 2-way link.

I think what changed, according to the Bigbang description, was the default setting of 2-ways, not the way the links are generated.

Right... but even with the old default setting of 100%, the majority of two-ways would be created from the linking of orphaned sectors. I'm just curious why it's done that way, and whether the resulting universe has significantly different properties than one generated with a higher number of initial warps. More small bubbles and dead ends, maybe?

Edit: I banged a game with 200% warp density. Most sectors had 6 warps. Not what I expected. Hmm.

I can't really say why. This is code I didn't write, and not something I'd change without a very good reason.

I think you see a lot of six warp sectors because when you start out with 200% 2-way warps, every sector starts out with 2 warps. If you use default, only 30% of sectors start out with 1 warp. So there's a high warp saturation to begin with, then you add in additional warps as you link up orphans. One way to look at it is that every sector with 4+ links in a default map will have 6 in a 200% bang.