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Stockfish - material balance/imbalance evaluation
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Tord Romstad



Joined: 08 Mar 2006
Posts: 1750
Location: Oslo, Norway
PostPost subject: Re: Stockfish - material balance/imbalance evaluation    Posted: Thu May 06, 2010 8:24 pm Reply to topic Reply with quote
Ralph Stoesser wrote:
Sven, we drift far away from the original thread topic, but in shorty I tried this:

The first step was to ensure there are no opponent pawns attacking my "blocked" pawn. For example after 1.e4 e5 2.d4 I didn't want to consider blacks e5 pawn as a blocked pawn.
Next I tried was to ensure there are no opponent pawns which possibly could attack my blocked pawn in a few moves, because either there are no such pawns on adjacent files or there are none in front of my blocked pawn.

That's all I have tried. Still easy to compute (I hate to makes things complicated too early), but it didn't help for bad bishop evaluation, at least in my tests. So I have canceled further tries with blocked pawns.


As you can probably guess, you are not the first person to experiment with this.

I've tried implementing a bad bishop penalty numerous times, using several different approaches: Counting all pawns on the bishop's color, only the blocked pawns, both blocked and unblocked pawns but with higher weights for blocked pawns, higher weights for pawns on central squares, and so on. I've never managed to make it work. The playing strength has always ended up unchanged or (more often) slightly lower.

This doesn't mean that it's impossible to make it work, of course. Perhaps we just haven't found exactly the right way to do it yet. With some luck, you might be able to do it.
Smile

Improving a mature chess program's evaluation function isn't easy. Just going through the code, identifying a missing piece of knowledge and implementing it in the most straightforward way will in most cases fail badly. Implementing it in a less straightforward way will usually fail even worse.
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Subject Author Date/Time
Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 05, 2010 4:39 pm
      Re: Stockfish - material balance/imbalance evaluation Marco Costalba Wed May 05, 2010 4:48 pm
            Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 05, 2010 5:37 pm
                  Re: Stockfish - material balance/imbalance evaluation Marco Costalba Wed May 05, 2010 5:47 pm
      Re: Stockfish - material balance/imbalance evaluation Jan Brouwer Wed May 05, 2010 5:49 pm
            Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Wed May 05, 2010 7:25 pm
                  Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 05, 2010 8:02 pm
                        Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Wed May 05, 2010 10:10 pm
                              Re: Stockfish - material balance/imbalance evaluation Milos Stanisavljevic Wed May 05, 2010 10:30 pm
                                    Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Wed May 05, 2010 10:47 pm
                                    Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 05, 2010 11:27 pm
                                          Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Thu May 06, 2010 1:23 am
                                                Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Thu May 06, 2010 9:07 am
                                                      Re: Stockfish - material balance/imbalance evaluation Sven Schüle Thu May 06, 2010 9:31 am
                                                            Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Thu May 06, 2010 9:52 am
                                                                  Re: Stockfish - material balance/imbalance evaluation Sven Schüle Thu May 06, 2010 10:48 am
                                                                        Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Thu May 06, 2010 12:08 pm
                                                                              Re: Stockfish - material balance/imbalance evaluation Tord Romstad Thu May 06, 2010 8:24 pm
                                                      Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Thu May 06, 2010 1:19 pm
                                                Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Fri May 07, 2010 9:34 pm
                                                      Re: Stockfish - material balance/imbalance evaluation Marco Costalba Sat May 08, 2010 12:48 pm
                                                            Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Sat May 08, 2010 1:47 pm
                                                            Re: Stockfish - material balance/imbalance evaluation Marcel van Kervinck Sat May 08, 2010 2:01 pm
                                          Re: Stockfish - material balance/imbalance evaluation Marco Costalba Thu May 06, 2010 11:40 am
                              Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Wed May 05, 2010 10:42 pm
      Re: Stockfish - material balance/imbalance evaluation Joona Kiiski Wed May 05, 2010 7:54 pm
            Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 05, 2010 8:28 pm
            Re: Stockfish - material balance/imbalance evaluation Larry Kaufman Sun May 27, 2012 7:31 pm
      Re: Stockfish - material balance/imbalance evaluation Tord Romstad Thu May 06, 2010 8:16 pm
            Re: Stockfish - material balance/imbalance evaluation James Coit Thu May 06, 2010 10:13 pm
            Re: Stockfish - material balance/imbalance evaluation Vratko Polák Thu May 06, 2010 11:38 pm
            Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Fri May 07, 2010 12:15 am
                  Re: Stockfish - material balance/imbalance evaluation Marco Costalba Fri May 07, 2010 5:39 am
                        Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Fri May 07, 2010 8:09 am
                              Re: Stockfish - material balance/imbalance evaluation Marco Costalba Fri May 07, 2010 8:25 am
                                    Re: Stockfish - material balance/imbalance evaluation Sven Schüle Fri May 07, 2010 9:48 am
                                          Re: Stockfish - material balance/imbalance evaluation Sven Schüle Fri May 07, 2010 10:31 am
                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Fri May 07, 2010 10:54 am
                                          Re: Stockfish - material balance/imbalance evaluation Miguel A. Ballicora Fri May 07, 2010 10:31 pm
                                                Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Sat May 08, 2010 1:33 pm
                                                      Re: Stockfish - material balance/imbalance evaluation Marco Costalba Sat May 08, 2010 2:29 pm
                                                            Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Sat May 08, 2010 4:24 pm
                                                                  Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Sat May 08, 2010 7:54 pm
                                                                        Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Sun May 09, 2010 3:19 pm
                                                                              Re: Stockfish - material balance/imbalance evaluation Marco Costalba Sun May 09, 2010 4:47 pm
                                                                                    Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Sun May 09, 2010 7:51 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Marco Costalba Sun May 09, 2010 10:47 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Sun May 09, 2010 11:22 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Marco Costalba Mon May 10, 2010 4:58 am
                                                                                          Re: Stockfish - material balance/imbalance evaluation Sven Schüle Mon May 10, 2010 7:39 am
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Mon May 10, 2010 10:22 am
                                                                                          Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Mon May 10, 2010 5:04 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Mon May 10, 2010 9:35 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Marco Costalba Tue May 11, 2010 11:19 am
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Tue May 11, 2010 1:51 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Tue May 11, 2010 9:38 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Marco Costalba Wed May 12, 2010 5:05 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Robert Hyatt Wed May 12, 2010 6:14 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Marco Costalba Wed May 12, 2010 6:39 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Thu May 13, 2010 12:51 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 12, 2010 8:13 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 12, 2010 9:15 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Marco Costalba Wed May 12, 2010 9:34 pm
                                                                                          Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Wed May 12, 2010 10:02 pm
                                                            Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Sat May 08, 2010 4:53 pm
                                                                  Re: Stockfish - material balance/imbalance evaluation Ralph Stoesser Sat May 08, 2010 7:03 pm
            Re: Stockfish - material balance/imbalance evaluation Vincent Diepeveen Wed Jul 28, 2010 6:10 pm
                  Re: Stockfish - material balance/imbalance evaluation Milos Stanisavljevic Wed Jul 28, 2010 6:24 pm
                        Re: Stockfish - material balance/imbalance evaluation grzegorzs Thu Aug 05, 2010 5:36 pm
                  Re: Stockfish - material balance/imbalance evaluation Dann Corbit Wed Jul 28, 2010 6:43 pm
                        Re: Stockfish - material balance/imbalance evaluation Vincent Diepeveen Wed Jul 28, 2010 7:43 pm
                              Re: Stockfish - material balance/imbalance evaluation Vincent Diepeveen Wed Jul 28, 2010 7:44 pm
                                    Re: Stockfish - material balance/imbalance evaluation Joona Kiiski Wed Jul 28, 2010 7:55 pm
                                          Re: Stockfish - material balance/imbalance evaluation Vincent Diepeveen Wed Jul 28, 2010 8:30 pm
                                                Re: Stockfish - material balance/imbalance evaluation Milos Stanisavljevic Wed Jul 28, 2010 9:30 pm
                                                      Re: Stockfish - material balance/imbalance evaluation Vincent Diepeveen Wed Jul 28, 2010 10:11 pm
                                                            Re: Stockfish - material balance/imbalance evaluation Milos Stanisavljevic Wed Jul 28, 2010 10:31 pm
                                                                  Re: Stockfish - material balance/imbalance evaluation Vincent Diepeveen Wed Jul 28, 2010 10:57 pm
                                                            Crazy talk Ben-Hur Carlos Langoni Wed Jul 28, 2010 11:07 pm
                                                                  Re: Crazy talk Vincent Diepeveen Wed Jul 28, 2010 11:36 pm
                                                Re: Stockfish - material balance/imbalance evaluation Ben Stoker Wed Jul 28, 2010 10:07 pm
                                                      Re: Stockfish - material balance/imbalance evaluation Vincent Diepeveen Sun Aug 08, 2010 1:54 pm
                              Re: Stockfish - material balance/imbalance evaluation Robert Hyatt Wed Jul 28, 2010 8:27 pm
                                    Re: Stockfish - material balance/imbalance evaluation Dann Corbit Wed Jul 28, 2010 9:30 pm
                              Re: Stockfish - material balance/imbalance evaluation Wylie Garvin Tue Aug 10, 2010 10:00 pm
      Re: Stockfish - material balance/imbalance evaluation Tu Ngoc Trung Sun May 27, 2012 2:22 am
            Re: Stockfish - material balance/imbalance evaluation Ferdinand Mosca Sun May 27, 2012 10:01 am
                  Re: Stockfish - material balance/imbalance evaluation Tu Ngoc Trung Mon May 28, 2012 3:19 am
            Re: Stockfish - material balance/imbalance evaluation Eelco de Groot Mon May 28, 2012 4:19 am
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