How does LZ decide which move to play?

[SanDiego]

@flovo

For AI ko fights are hard to read.

As a human you simply count the ko threats for each colour.
The AI has to play out all variants for this fight. So it seems reasonable to assume that AIs tend to avoid ko fights.

Having studied a few AI games, I strongly disagree with this. AlphaGo Zero and LZ handle ko fights at a scale that is far beyond what humans can read. I am not an expert but my understanding is that those AIs don’t have to play out all variants to reach a conclusion.
Check out my post here, where I share an ELF vs. LZ game I ran on my computer:

ELF OpenGo weirdness

FWIW the finished game. ELF v2 (black) wins by 1.5 point. An epic game with two large ko fights towards the end (each ko fight lasts more than 70 moves…). I ran another game with ELF as white and 5.5 komi. LZ resigned. I am now very tempted to switch to ELF for game analysis, despite the weird opening analysis showed by @mark5000.

@lysnew

Very often its best moves (in my games) was just wasting ko threats.

I don’t believe this either, and even if it was the case we humans would not be able to judge. What I believe is that when the AI throws away a ko threat it’s because it estimates that it won’t have an impact on the result.