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Jorge Pichard

Joined: 09 Mar 2006
Posts: 2558

Post subject: Re: We should reconsider the value of the Queen.............    Posted: Sun Apr 08, 2012 12:37 am

Sven Schüle wrote:
pichy wrote:
Sven Schüle wrote:
 Andre wrote: So here White just plays e4 What is the value of the two queens?

For an engine, as well as - within certain limits - for a human, piece values (and also positional values) are needed only to get an approximated value of a position where the search (resp. the human analysis) can't go deep enough to determine the "true value" of the position. In your example above it is a forced mate in three plies for white, so neither engines nor (strong enough) humans need to consider any piece values here.

Therefore, your example does not say anything about pieces values that should be used by programs.

You are forgetting something very important. You are not following
[...]

I am not forgetting anything here, Jorge. I stated that your example is 100% unrelated to "piece values" since it is a mate in 3 plies. A similar statement applies to your other tactical examples where the queen value is fully unimportant (either the queen gets lost immediately, or the enemy can promote his passed pawn after white trades Q vs. RB). These examples are about search, not about the value of a queen when evaluating (leaf) positions.

We can surely debate about the choice of queen values in today's engines and possible improvements. Maybe you are right when stating that for some programs the queen value is too small. You can be sure, though, that this is not the case for the vast majority of the current "top" engines since their evaluation parameters are well-tuned. In any case, I don't say that your position is "wrong", the main issue I see with your posts (apart from the font size, of course) is the choice of your example positions which are unrelated to the points you want to make, in my opinion.

Sven

Some of you might be correct and I am not saying that the value of the Queen is too high, all that I am saying is that after the middlegame around move 40 or starting the endgame the value of the Queen disminish and it should not be left with the same value throughout the game.
The relative value of pieces changes as a game progresses to the endgame. The relative value of pawns and rooks may increase, and the value of bishops may increase also, though usually to a lesser extent. The knight tends to lose some power, and the strength of the queen may be slightly lessened, as well. Some examples follow.
• A queen versus two rooks
• In the middlegame they are equal
• In the endgame, the two rooks are somewhat more powerful. With no other pieces on the board, two rooks are equal to a queen and a pawn

We should reconsider the value of the Queen to no more than 8.5 in the endgame stage and here are some positions to look at

[size=18]In the first position a Bishop and a Rook value at 8 points give us a draw [:wink/size]
[D]8/8/8/3kb3/3r4/3KQ3/8/8 w - - 0 1
[D]8/8/8/3kn3/3r4/2QK4/8/8 w - - 0 1
Here is another interesting position where the Queen is not as strong as two rook

[D]3k4/2rr4/8/8/8/8/8/3KQ3 w - - 0 1

I only recommend some adjustment to some engines not all of the top ones and the any Chess engine could easily be modified to adjust the value of the Queen depending on the stage of the game like Lasker recommended before the era of computer, for instance if the game has not reached the endgame which is normally after move 40 then this logic could be applied.

if(Condition)
Statement1;
else
Statement2;

Or something like this depending on the variable used for the Queen

if(Number of moves < than 40)
Statement1;value of Q=10.5
else
Statement2; value of set Q=8.5
 Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First
Subject Author Date/Time
Jorge Pichard Fri Apr 06, 2012 1:17 pm
H.G.Muller Fri Apr 06, 2012 1:29 pm
Jorge Pichard Fri Apr 06, 2012 3:32 pm
H.G.Muller Fri Apr 06, 2012 4:35 pm
Jorge Pichard Fri Apr 06, 2012 5:10 pm
S.Taylor Sun Apr 08, 2012 9:53 pm
Graham Banks Fri Apr 06, 2012 6:10 pm
Jorge Pichard Fri Apr 06, 2012 7:40 pm
Lucas Braesch Sat Apr 07, 2012 2:06 am
Jorge Pichard Sat Apr 07, 2012 2:30 am
André Lopez Sat Apr 07, 2012 3:09 am
Terry McCracken Sat Apr 07, 2012 3:15 am
Jorge Pichard Sat Apr 07, 2012 5:31 am
Terry McCracken Sat Apr 07, 2012 4:01 pm
Matthew R. Brades Sat Apr 07, 2012 8:28 am
Jorge Pichard Sat Apr 07, 2012 10:06 am
Jorge Pichard Sat Apr 07, 2012 10:31 am
Jorge Pichard Sat Apr 07, 2012 11:34 am
Guenther Simon Sat Apr 07, 2012 11:45 am
Jorge Pichard Sat Apr 07, 2012 1:05 pm
Sven Schüle Sat Apr 07, 2012 4:39 pm
Jorge Pichard Sat Apr 07, 2012 5:50 pm
Sven Schüle Sat Apr 07, 2012 11:26 pm
Re: We should reconsider the value of the Queen............. Jorge Pichard Sun Apr 08, 2012 12:37 am
Ronald de Man Sun Apr 08, 2012 1:14 am
Jorge Pichard Sun Apr 08, 2012 1:50 am
Ronald de Man Sun Apr 08, 2012 2:50 am
Jorge Pichard Sun Apr 08, 2012 4:51 am
Adam Hair Sun Apr 08, 2012 1:28 pm
Jorge Pichard Sun Apr 08, 2012 2:47 pm
Jorge Pichard Sun Apr 08, 2012 3:24 pm
Guenther Simon Sun Apr 08, 2012 4:08 pm
Jorge Pichard Sun Apr 08, 2012 5:20 pm
Jorge Pichard Sun Apr 08, 2012 7:40 pm
Sven Schüle Sun Apr 08, 2012 9:35 pm
Jorge Pichard Sun Apr 08, 2012 10:36 pm
Sven Schüle Sun Apr 08, 2012 11:30 pm
Jorge Pichard Sun Apr 08, 2012 11:42 pm
Adam Hair Mon Apr 09, 2012 12:26 am
Jorge Pichard Mon Apr 09, 2012 4:46 pm
Vincent Diepeveen Sat Apr 07, 2012 4:56 pm
H.G.Muller Sat Apr 07, 2012 5:32 pm
Jorge Pichard Sat Apr 07, 2012 6:04 pm
Maurizio Maglio Sat Apr 07, 2012 9:55 pm
Jimmy Huggins Sat Apr 07, 2012 10:12 pm
Jorge Pichard Sat Apr 07, 2012 11:03 pm
André Lopez Sun Apr 08, 2012 12:40 am
Richard Sutherland Sat Apr 07, 2012 6:47 pm
Jorge Pichard Sat Apr 07, 2012 9:08 pm

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