TalkChess.com
Hosted by Your Move Chess & Games

Author Message
Arjun Temurnikar

Joined: 15 Oct 2013
Posts: 204
Location: Singapore

Post subject: Re: Redundant knight    Posted: Fri Jun 20, 2014 3:03 pm

Lyudmil Tsvetkov wrote:
arjuntemurnikar wrote:
I think this is already covered by the imbalance table, if not it should be.

There is no reason for the redundant piece evaluation term -- it is simply redundant -- pun intended.

 Lyudmil Tsvetkov wrote: So when was rook redundacy removed from SF? The last time I checked SF code, a month ago, it was still there. I also know that at the end of last year someone submitted a test to remove redundant rooks, and it failed. This is on the framework history page.

Can you point to the line of code that does redundancy evaluation in SF? I can't find it.

Your same-vein messages are redundant - pun not intended.

Imbalance will never take account of this, as this is a special term; in the same way as it will never take account of the queen vs 3 pieces imbalance.

It seems that I know SF code better than you and Lucas.

Please take a look at the below link:
http://tests.stockfishchess.org/tests/view/527ae0480ebc5945a2478d18

 Code: // Scale factors used when one side has no more pawns   35   35       const int NoPawnsSF[4] = { 6, 12, 32 };   36   36       37      -  // Polynomial material balance parameters   38      -  const Value RedundantQueen = Value(320);   39      -  const Value RedundantRook  = Value(554);   40   37       41   38       //                                  pair  pawn knight bishop rook queen   42   39       const int LinearCoefficients[6] = { 1852, -162, -1122, -183,  105,  26 };     @@ -102,6 +99,8 @@ namespace {   102   99       int imbalance(const int pieceCount[][PIECE_TYPE_NB]) {   103   100       104   101         const Color Them = (Us == WHITE ? BLACK : WHITE);     102    +    const Value RedundantQueen = Value(320);     103    +    const Value RedundantRook  = Value((pieceCount[Us][PAWN] + pieceCount[Them][PAWN]) * 40);   105   104       106   105         int pt1, pt2, pc, v;   107   106         int value = 0;

There are a number of things wrong with your post above.

1. You point to a 3rd party repo of stockfish, not the official one by Marco.
2. Not only is it a 3rd party repo, it is hopelessly out of date (8+ months!!)
3. You point to a test that is incomplete and has a <0.1 p-value, so it is completely unreliable.

Here is the correct commit that removes the redundant terms: https://github.com/mcostalba/Stockfish/commit/52ae0efccffcce7f095cc4bae7bf90fe7a3b467b

and here is the followup: https://github.com/mcostalba/Stockfish/commit/3ed86ed3f95f712587bea62f4a7fc474812db458

So as you can see -- these terms are easily incorporated by the material imbalance table.

The Q vs 3 minors are also incorporated into the table. It is just a matter of tuning them. I don't know why these misconceptions are flying around that Q vs 3 minors is a "special case" that cannot be part of the table. That is simply wrong!

Unfortunately, since the array is quite large, it is impossible to do the tuning in one CLOP session. So Joerg is probably breaking it down into multiple sessions for each piece type, but this creates problems as all the terms are inter-related. There may also be the possibility that he is running into local maximas.

The material imbalance tuning will take a very very long time as it is a gigantic undertaking, so please be patient. (...and kudos to Joerg for even daring to attempt it on his own! )
 Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First
Subject Author Date/Time
Lyudmil Tsvetkov Fri Jun 20, 2014 10:38 am
H.G.Muller Fri Jun 20, 2014 11:03 am
Lyudmil Tsvetkov Fri Jun 20, 2014 11:54 am
H.G.Muller Fri Jun 20, 2014 4:01 pm
Lucas Braesch Fri Jun 20, 2014 11:21 am
Lyudmil Tsvetkov Fri Jun 20, 2014 12:03 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 11:37 am
Louis Zulli Fri Jun 20, 2014 11:50 am
Lyudmil Tsvetkov Fri Jun 20, 2014 12:13 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 12:36 pm
Louis Zulli Fri Jun 20, 2014 1:27 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 2:09 pm
Arjun Temurnikar Fri Jun 20, 2014 2:32 pm
Louis Zulli Fri Jun 20, 2014 4:12 pm
Louis Zulli Fri Jun 20, 2014 4:21 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 4:30 pm
Robert Hyatt Sat Jun 21, 2014 2:51 am
Lyudmil Tsvetkov Sat Jun 21, 2014 6:53 am
Arjun Temurnikar Fri Jun 20, 2014 1:41 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 2:26 pm
Re: Redundant knight Arjun Temurnikar Fri Jun 20, 2014 3:03 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 3:40 pm
Arjun Temurnikar Fri Jun 20, 2014 4:43 pm
Joerg Oster Fri Jun 20, 2014 2:33 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 3:12 pm
Arjun Temurnikar Fri Jun 20, 2014 3:19 pm
Arjun Temurnikar Fri Jun 20, 2014 3:35 pm
Lyudmil Tsvetkov Fri Jun 20, 2014 3:51 pm
Lucas Braesch Fri Jun 20, 2014 6:47 pm
Arjun Temurnikar Fri Jun 20, 2014 7:23 pm
Lyudmil Tsvetkov Sat Jun 21, 2014 1:31 am
Bernhard Bauer Sat Jun 21, 2014 5:31 am
Lyudmil Tsvetkov Sat Jun 21, 2014 6:57 am
H.G.Muller Sat Jun 21, 2014 7:54 am
Matthew R. Brades Sat Jun 21, 2014 8:04 am
Lyudmil Tsvetkov Sat Jun 21, 2014 8:57 am
Lyudmil Tsvetkov Sat Jun 21, 2014 8:48 am
H.G.Muller Sat Jun 21, 2014 9:19 am
Lyudmil Tsvetkov Sat Jun 21, 2014 10:00 am
Bernhard Bauer Sat Jun 21, 2014 5:22 am
Lyudmil Tsvetkov Sat Jun 21, 2014 7:07 am
Lyudmil Tsvetkov Sat Jun 21, 2014 9:30 am
H.G.Muller Sat Jun 21, 2014 9:45 am
Lyudmil Tsvetkov Sat Jun 21, 2014 10:21 am
H.G.Muller Sat Jun 21, 2014 11:31 am
Lyudmil Tsvetkov Sat Jun 21, 2014 11:38 am
Lyudmil Tsvetkov Sat Jun 21, 2014 11:38 am
H.G.Muller Sat Jun 21, 2014 11:52 am
Arjun Temurnikar Sat Jun 21, 2014 2:23 pm
Kevin Hearn Sat Jun 21, 2014 10:30 am
Lyudmil Tsvetkov Sat Jun 21, 2014 11:16 am
Bernhard Bauer Sat Jun 21, 2014 11:36 am
Lyudmil Tsvetkov Sat Jun 21, 2014 12:10 pm
H.G.Muller Sat Jun 21, 2014 12:16 pm
Lyudmil Tsvetkov Sat Jun 21, 2014 11:59 am
Lyudmil Tsvetkov Sat Jun 21, 2014 12:58 pm
H.G.Muller Sat Jun 21, 2014 12:11 pm

 Jump to: Select a forum Computer Chess Club Forums----------------Computer Chess Club: General TopicsComputer Chess Club: Tournaments and MatchesComputer Chess Club: Programming and Technical DiscussionsComputer Chess Club: Engine Origins Other Forums----------------Chess Thinkers ForumChess Players ForumForum Help and Suggestions
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum