For those that like to toy with Ethereal...

[Dann Corbit]

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

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        R = ( ( 13 + depth ) >> 2 ) + MIN(3, (eval - beta) / 185);

[Dann Corbit]

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

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

[Dann Corbit]

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

[mar]

Hmm, could this be a hint that Fritz 17 is Ethereal? http://talkchess.com/forum3/viewtopic.php?f=2&t=72170

[MikeB]

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]

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]

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

[Dann Corbit]

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.

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   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 %
 

[AndrewGrant]

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.

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   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%)
SPRT | 10.0+0.1s Threads=1 Hash=8MB
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]

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 %
 

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NMPFormula vs master DIFF

ELO   | 0.62 +- 1.98 (95%)
SPRT  | 10.0+0.1s Threads=1 Hash=8MB
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.