A bit of relief. It turns out simple linear regression is most pessimistic in its predictions, and it doesn't fit the data very well anyway. Two competing models are quadratic and linear that only takes into account last 30 networks.

So why linear on just last 30 networks? Well, earlier networks were smaller, and code got changed in the meantime, and bugs fixed. Maybe it makes sense to ignore how older code / network size progressed and focus on a current state. This seams like a realistic lower bound of progress. At around 10,000 internal Elo, LZ would sit comfortably in top 100 on CGoS, and maybe even top 50. Domination expected around Elo 11,000.

Quadratic is the most optimistic of three, and it also fits data very well. It says, the stronger the network is, more will it's Elo gain be transferred to CGoS. Reasoning behind it is that earlier networks could exploit weaknesses in previous iterations, and achieve easy wins, but those exploits weren't so generalizable to other opponents. As newer networks have fewer obvious exploits, it requires real strength gain to get promoted. Internal Elo of 10,000 would be enough to match top bots on CGoS.

So how much of internal Elo gain can a new network expect anyway?