## For those that like to toy with Ethereal...

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Dann Corbit
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### For those that like to toy with Ethereal...

You can get a very close approximation to the Stockfish null move pruning with this formula:

Code: Select all

``````        R = ( ( 13 + depth ) >> 2 ) + MIN(3, (eval - beta) / 185);
``````
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But sharing ideas is an even greater virtue. We have another word for this. It is called teaching.

Dann Corbit
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### Re: For those that like to toy with Ethereal...

E.g. you can experiment with it like this easily:

Code: Select all

``````#ifdef OLD_PRUNE
R = 4 + depth / 6 + MIN(3, (eval - beta) / 200);
#else
R = ( ( 13 + depth ) >> 2 ) + MIN(3, (eval - beta) / 185);
#endif
``````
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.

Dann Corbit
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### Re: For those that like to toy with Ethereal...

In a test (every early) the Ethereal pruning is doing better than the Stockfish style.
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.

mar
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Full name: Martin Sedlak

### Re: For those that like to toy with Ethereal...

Hmm, could this be a hint that Fritz 17 is Ethereal? viewtopic.php?f=2&t=72170
Martin Sedlak

MikeB
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### Re: For those that like to toy with Ethereal...

Dann Corbit wrote:
Wed Oct 30, 2019 10:40 pm
In a test (every early) the Ethereal pruning is doing better than the Stockfish style.
Please define 'better' , can I assume you meant in position testing as opposed to head to head combat??

AndrewGrant
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### Re: For those that like to toy with Ethereal...

MikeB wrote:
Thu Oct 31, 2019 1:13 am
Dann Corbit wrote:
Wed Oct 30, 2019 10:40 pm
In a test (every early) the Ethereal pruning is doing better than the Stockfish style.
Please define 'better' , can I assume you meant in position testing as opposed to head to head combat??
http://chess.grantnet.us/viewTest/3607/

Going to figure things out

Dann Corbit
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### Re: For those that like to toy with Ethereal...

MikeB wrote:
Thu Oct 31, 2019 1:13 am
Dann Corbit wrote:
Wed Oct 30, 2019 10:40 pm
In a test (every early) the Ethereal pruning is doing better than the Stockfish style.
Please define 'better' , can I assume you meant in position testing as opposed to head to head combat??
I have a match running. It's set for 100K games, but I won't let it go that far.
When I left, SF pruning was ever so slightly ahead
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.

Dann Corbit
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Joined: Wed Mar 08, 2006 7:57 pm
Location: Redmond, WA USA
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### Re: For those that like to toy with Ethereal...

No difference in my test, but I discovered that Arena was logging like mad (I had a 550 MB arena.debug file) so I think the result cannot be trusted.

Code: Select all

``````   Program                          Elo    +   -   Games   Score   Av.Op.  Draws
1 Ethereal-stopr                 : 3333   11  11  1475    50.1 %   3333   58.6 %
2 Ethereal-ethpr                 : 3333   11  11  1475    49.9 %   3333   58.6 %
``````
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.

AndrewGrant
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### Re: For those that like to toy with Ethereal...

Dann Corbit wrote:
Thu Oct 31, 2019 6:55 pm
No difference in my test, but I discovered that Arena was logging like mad (I had a 550 MB arena.debug file) so I think the result cannot be trusted.

Code: Select all

``````   Program                          Elo    +   -   Games   Score   Av.Op.  Draws
1 Ethereal-stopr                 : 3333   11  11  1475    50.1 %   3333   58.6 %
2 Ethereal-ethpr                 : 3333   11  11  1475    49.9 %   3333   58.6 %
``````
NMPFormula vs master DIFF

ELO | 0.62 +- 1.98 (95%)
LLR | -2.96 (-2.94, 2.94) [0.00, 5.00]
Games | N: 46370 W: 9180 L: 9097 D: 28093
Not bad, but Ill stick with current master.

AndrewGrant
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### Re: For those that like to toy with Ethereal...

AndrewGrant wrote:
Thu Oct 31, 2019 9:45 pm
Dann Corbit wrote:
Thu Oct 31, 2019 6:55 pm
No difference in my test, but I discovered that Arena was logging like mad (I had a 550 MB arena.debug file) so I think the result cannot be trusted.

Code: Select all

``````   Program                          Elo    +   -   Games   Score   Av.Op.  Draws
1 Ethereal-stopr                 : 3333   11  11  1475    50.1 %   3333   58.6 %
2 Ethereal-ethpr                 : 3333   11  11  1475    49.9 %   3333   58.6 %
``````

Code: Select all

``````NMPFormula vs master DIFF

ELO   | 0.62 +- 1.98 (95%)