Eelco de Groot

Joined: 12 Mar 2006 Posts: 2591 Location: Groningen
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Post subject: Re: Stockfish - material balance/imbalance evaluation Posted: Sat May 08, 2010 4:53 pm |
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| mcostalba wrote: |
| Ralph Stoesser wrote: |
@Marco, at least your hidden automatic tuning machine cannot fix bugs, but we humans can.
evaluate.cpp, line 145
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Wow ! This is a bug, but to properly fix we need to retune all !
If we rewrite the labes as should be:
| Code: |
const Score ThreatBonus[8][8] = {
{ Z, Z, Z, Z, Z, Z, Z, Z },
{ Z, S(18,37), Z, S(37,47), S(55,97), S(55,97), Z, Z }, // not used
{ Z, S(18,37), S(37,47), Z, S(55,97), S(55,97), Z, Z }, // KNIGHT attacks
{ Z, S( 9,27), S(27,47), S(27,47), Z, S(37,47), Z, Z }, // BISHOP attacks
{ Z, S(27,37), S(27,37), S(27,37), S(27,37), Z, Z, Z }, // ROOK attacks
{ Z, Z, Z, Z, Z, Z, Z, Z }, // QUEEN attacks
{ Z, Z, Z, Z, Z, Z, Z, Z }, // not used
{ Z, Z, Z, Z, Z, Z, Z, Z } // not used
};
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we see that evaluation for the queen is completely missing ! and that also evaluation for a KNIGHT attacking a BISHOP, for a BISHOP attacking a ROOK and a ROOK attacking a QUEEN are all missing.
So we need to retune all !
Thanks, yes, this is a case where we will need to use autmatic tuning  |
Is this labeling correct?
| Code: |
const Score ThreatBonus[8][8] = {
{ Z, Z, Z, Z, Z, Z, Z, Z }, // BISHOP PAIR attacks
{ Z, S(18,37), Z, S(37,47), S(55,97), S(55,97), Z, Z }, // PAWN
attacks
{ Z, S(18,37), S(37,47), Z, S(55,97), S(55,97), Z, Z }, // KNIGHT attacks
{ Z, S( 9,27), S(27,47), S(27,47), Z, S(37,47), Z, Z }, // BISHOP attacks
{ Z, S(27,37), S(27,37), S(27,37), S(27,37), Z, Z, Z }, // ROOK attacks
{ Z, Z, Z, Z, Z, Z, Z, Z }, // QUEEN attacks
{ Z, Z, Z, Z, Z, Z, Z, Z }, // KING attacks
{ Z, Z, Z, Z, Z, Z, Z, Z } // not used
};
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I find it still very strange that the table still works with Knight-Knight attacks, Bishop-Bishop coefficients that are not zero and others that should be zero. I have not tried the new version yet. The coefficients are small but still strange that it could be tuned at all... I had been looking at those Z,Z,Z tables but assumed somehow that the Bishop pair was not included in the table Rainbow Serpent by the way has KING attacks but if this interpretation is correct it was actually QUEEN attacks ? If so I can say that QUEEN attacks should work Don't know about King attacks now... If this only explains why Tord Marco And Joona coud not find more elos in the table, that is not so surprising anymore then Thanks to Ralph! One more bug find like this and Stockfish can overtake Rybka 4 when she comes out
Eelco _________________ Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan |
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