Leela - Dance of the knights

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Glarean
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Full name: Walter Eigenmann
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Leela - Dance of the knights

Post by Glarean » Fri May 22, 2020 6:40 pm

In a tournament with 17 Engines, I investigated whether Leela & Co. or AlphaBeta played better.
The trend is toward NN, but at the moment we're still tied.
Hardware/Software: AMD Ryzen7 2700X 3,7 GHz - 1024 Mb Hash - 8Cores/16Threads - GPU RTX2080 - GUI Fritz 17 - 4min & 2sec TC - 5-Moves-Opening-Book - 5-men-Syzygy-Tablebases

Image

The Leela victories are very impressive. There are numerous positional highlights.
Above all Leela can handle the knights with virtuosity.

One of four examples:
3qkb1r/1r3pp1/1nn1p2p/p2pP2P/1ppP4/1PP2NR1/P2BNPP1/1R1Q2K1 w k
Image

Ne1-c2-e3 !

The whole report and the download files (CBH/PGN/EPD) here:
https://glarean-magazin.ch/2020/05/22/c ... urnaments/

Greetings: Walter

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Ajedrecista
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Re: Leela - Dance of the knights.

Post by Ajedrecista » Fri May 22, 2020 7:25 pm

Hello Walter:

Thanks for the games and your usual effort! This dance of the knights deserves a soundtrack. How about one of the same name?

Prokofiev - Dance of the Knights

Talking about dancing knights, I still remember the game in the 2010 WCC where Anand did 13 consecutive knight moves in one of the games (from move 22 to move 34):

Viswanathan Anand vs Veselin Topalov (2010 WCC, 6th game



I remember that I followed that game at ChessBomb broadcast back in the days when the 2010 eruptions of Eyjafjallajökull caused an important air travel disruption.

Regards from Spain.

Ajedrecista.

Glarean
Posts: 226
Joined: Sun Oct 05, 2008 11:04 am
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Full name: Walter Eigenmann
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Re: Leela - Dance of the knights

Post by Glarean » Fri May 22, 2020 7:45 pm

Thanks for your feedback.

Yes, it's the age-old struggle at Prokofiev and Anand and everywhere:

Knight against Knight...

Image

;-)

Greetings: Walter

brianr
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Re: Leela - Dance of the knights

Post by brianr » Fri May 22, 2020 8:02 pm

Lc0 and most of the other NN engines should be run with 2 threads, not 1 (or number-of-GPUs + 1).
Incidentally, more than that actually hurts performance (very unlike A/B engines).

Dann Corbit
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Re: Leela - Dance of the knights

Post by Dann Corbit » Fri May 22, 2020 8:39 pm

Glarean wrote:
Fri May 22, 2020 6:40 pm

The whole report and the download files (CBH/PGN/EPD) here:
https://glarean-magazin.ch/2020/05/22/c ... urnaments/

Greetings: Walter
The PGN archive also contains ChessBase format.
Taking ideas is not a vice, it is a virtue. We have another word for this. It is called learning.
But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.

Glarean
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Location: Switzerland
Full name: Walter Eigenmann
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Re: Leela - Dance of the knights

Post by Glarean » Fri May 22, 2020 9:55 pm

You're right, thanks for the advice!
Corrected.

Glarean
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Full name: Walter Eigenmann
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Re: Leela - Dance of the knights

Post by Glarean » Fri May 22, 2020 10:01 pm

brianr wrote:
Fri May 22, 2020 8:02 pm
Lc0 and most of the other NN engines should be run with 2 threads, not 1 (or number-of-GPUs + 1).
As far as I know, it's not important, one core is enough. The calculation of the NN engines is done almost exclusively via the GPU. BTW, a very strong Nvidia-RTX2080 was used here...

brianr
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Re: Leela - Dance of the knights

Post by brianr » Fri May 22, 2020 10:38 pm

Glarean wrote:
Fri May 22, 2020 10:01 pm
brianr wrote:
Fri May 22, 2020 8:02 pm
Lc0 and most of the other NN engines should be run with 2 threads, not 1 (or number-of-GPUs + 1).
As far as I know, it's not important, one core is enough. The calculation of the NN engines is done almost exclusively via the GPU. BTW, a very strong Nvidia-RTX2080 was used here...
Exactly 2 threads should be used for Lc0 with one GPU (which is why it is the default value)
This turns out to be the optimal way to collect batches of work to keep the GPU busy.
More than two incurs locking penalties (currently).
Less than two is unlikely to feed enough work to the GPU.
The speed of the CPUs is somewhat important, with higher clock rates being better.
Up to you, of course.
Last edited by brianr on Fri May 22, 2020 10:43 pm, edited 1 time in total.

Glarean
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Full name: Walter Eigenmann
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Re: Leela - Dance of the knights

Post by Glarean » Fri May 22, 2020 10:42 pm

I'd be interested: Any programming or statistical evidence to support that claim?

brianr
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Re: Leela - Dance of the knights

Post by brianr » Fri May 22, 2020 10:44 pm

Just ask on the Leela chess Discord in the #help channel.

https://discord.com/channels/4254194825 ... 1713154049

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