but i'd love to see C2's move that nearly knocked Elf off her perch - from the authors' remarks about ladders, it looks like Elf walked under one and nearly paid the price, but made a stunning recovery.

At this moment in time, it looks like ELF v.2 (05dbca15) is losing solidly against the strongest LZ network. The match is not over, of course:

...what's the point in jumping with keima if white's only going to butt heads against it and black more or less has to play where she would have done anyway with the more (to me, at least) natural-looking press instead? i suppose there must be some advantage to the keima that doesn't become obvious until several hundred moves later...

What happened in these two games?

W: ELF V2
B: LeelaZero #204

http://zero.sjeng.org/viewmatch/c327835 ... viewer=wgo
http://zero.sjeng.org/viewmatch/7b181c4 ... viewer=wgo

Can anyone confirm that ELF can correctly read ladders now (perhaps with the right number of playouts or visits)? I saw ELF v2 still making questionable ladder moves in a couple of games against LZ #204.

Ladders create a predictable sequence of moves for each player that can span the entire board. In contrast to humans, Silver et al. (2017) observes that deep RL models learn these tactics very late in training. To gain further insight into this phenomenon, we curate a dataset of 100 ladder scenarios (as described in Appendix B.2) and evaluate the model’s ladder handling abilities throughout training.

In general, ladder play improves with a fixed learning rate and degrades after the learning rate is reduced before once again recovering. While the network improves on ladder moves, it still makes mistakes even late in training. In general, increasing the number of MCTS rollouts from 1,600 to 6,400 improves ladder play, but mistakes are still made.

We have released ELF Opengo's all selfplay data and checkpoint models, a paper, a windows executable, as well as its analysis on all professional games ever played!
https://arxiv.org/abs/1902.04522
https://facebook.ai/developers/tools/elf-opengo

I hope I don't get in trouble for answering in the wrong place:

I believe the keima increases black's ability to take sente.

Which seems to be a thing now.

I also don't think it is a given that white is going to butt heads. I've seen O-02 played as well