Life In 19x19
http://lifein19x19.com/

KataGo Ladder Blindness
http://lifein19x19.com/viewtopic.php?f=18&t=18517
Page 1 of 1

Author:  sunshower [ Wed Dec 15, 2021 9:50 am ]
Post subject:  KataGo Ladder Blindness

As a long-time lurker I guess this is as good a first post as any.

I encountered this position some time ago (back in June I think), while pitching one of KataGo's distributed networks against Leela Zero. KataGo is Black and Leela is White. I didn't post this earlier because I was interested to see, if the training would rectify it on its own. But as it is, even the current networks enter into this variation (despite high playouts) and do not realize that the ladder doesn't work until it's too late.

Interestingly enough, the final network of the pre-distributed run (b40c256x2-s509) has no problems at all with this ladder. Is it possible that there is a risk of introducing new blind spots as the training goes on?

I think this is the move in question:

Image


The image above shows the analysis of the currently highest-rated 40b network (b40c256-s1049) and it suggests a game-losing blunder after more than 500k playouts.
I remember lightvector saying (on this forum I think) that he could insert these kind of positions into the training, so I hope this is useful.

The sgf file contains only one variation (the original I encountered), but some networks might propose a different order of moves.

Attachments:
KataGo Blindspot.sgf [825 Bytes]
Downloaded 425 times

Author:  Schachus [ Thu Dec 16, 2021 11:20 am ]
Post subject:  Re: KataGo Ladder Blindness

sorry for being stupid, I assume it is blacks move.

Where is the ladder? The only potential ladder I can see is the one starting with the move that has 16 playouts in your picture, but it doesnt seem to work(if black pulls out 3 times then capturing the one stone will put another in atari) or am I mistaken? Edit: I see you provided an sgf, I cant open it currently unfortunately, but will check it later

Author:  sunshower [ Thu Dec 16, 2021 12:06 pm ]
Post subject:  Re: KataGo Ladder Blindness

Sorry, maybe the post is a bit confusing. The picture does not show the actual ladder but the move that KataGo wants to play because it wrongly assumes that there is a ladder. The attached sgf file goes a few moves further and includes the ladder in question.

Author:  lightvector [ Sun Dec 19, 2021 7:38 am ]
Post subject:  Re: KataGo Ladder Blindness

Thanks for the example! There appears to be a deep ladder breaker tactic that is being read incorrectly, it's not exactly a blind spot, just some misreading. I'll see if this can be a useful training sample.

Author:  Joaz Banbeck [ Sun Dec 19, 2021 11:16 pm ]
Post subject:  Re: KataGo Ladder Blindness

sunshower wrote:
...The attached sgf file ...



Page 1 of 1 All times are UTC - 8 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/