Piece/square table challenge
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Re: Piece/square table challenge
I played a while with several posted PST's and especially the Adam Hair PST's are a lot of fun, lot's of instant solved tactical shots but in eng-eng it does bad like some of the others I tried. The latter is no surprise, piece values + PST's need to be in balance with eval.
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Re: Piece/square table challenge
I totally dislike adam's set because it is not symmetric to files and it can be interesting if you can test a symmetric version of his set by simply replacing every 2 numbers by the average of them so if knight at b3 and knight at g3 have different values you replace the values simply by the average.PK wrote:Results for today:
Lyudmil's set comes third (and the best among "general use" tables). It is worth nothing that it scored worse against Mikko's set, but relatively better against "doctored" sets).Code: Select all
Program Elo + - Games Score Av.Op. Draws 1 Rodent 1.3 (build adam) : 2081 11 11 3642 64.9 % 1974 18.8 % 2 Rodent 1.3 (build pawel) : 2060 10 10 3641 61.4 % 1979 22.3 % 3 Rodent 1.3 (build lyudmil) : 2016 13 13 2060 46.9 % 2038 22.4 % 4 Rodent 1.3 (build mikko+) : 2006 12 12 2582 50.4 % 2003 21.4 % 5 Rodent 1.3 (build ufo) : 2000 10 10 3524 51.8 % 1987 24.5 % 6 Rodent 1.3 (build lucas) : 1965 13 13 2026 42.1 % 2021 24.7 % 7 Rodent 1.3 (build ERROR) : 1935 14 14 2036 36.9 % 2028 22.0 % 8 Rodent 1.3 (build daniel) : 1836 15 15 2063 23.7 % 2040 17.5 %
More news tomorrow. Enjoy!
I wonder if this version cannot score even better because I doubt the idea of attacking the opponent king when you even do not know where it is can be good.
In most cases the king go to the king side with symmetric evaluation and still attacking in that side may change the decision of the opponent in part of the cases because the opponent can see for tactical reasons in some cases that it is better not to go to the king side.
I also think that attacking in the queen side can also be effective even the opponent castle short because there are other targets to attack in a chess game and not only the opponent king.
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Re: Piece/square table challenge
I agree. As a general PST it's probably not so useful.Uri Blass wrote: I totally dislike adam's set because it is not symmetric to files and it can be interesting if you can test a symmetric version of his set by simply replacing every 2 numbers by the average of them so if knight at b3 and knight at g3 have different values you replace the values simply by the average.
I wonder if this version cannot score even better because I doubt the idea of attacking the opponent king when you even do not know where it is can be good.
In most cases the king go to the king side with symmetric evaluation and still attacking in that side may change the decision of the opponent in part of the cases because the opponent can see for tactical reasons in some cases that it is better not to go to the king side.
I also think that attacking in the queen side can also be effective even the opponent castle short because there are other targets to attack in a chess game and not only the opponent king.
What I posted yesterday (fitting the table with a linear combination of symmetric tables and an asymmetric "tropism" table) is my first attempt at making something a bit more general based on Adam's table. The fit isn't very good, but that may not be so important for a number of reasons (not knowing how much noise there is on each value is one of them). The main point is to replicate the idea with a few tables and some weights.
Eventually, I plan to try the following: I identify interesting "targets", like the enemy king, a weak pawn, a strong square. Each of these is assigned a weight (to be tuned) and the product of the weight and the tropism value gets added to the PST score. The weights could be game-phase dependent (attacking the king may be more important in the middle-game than the end-game, for instance). It'll be a while before I really get around to doing that though...
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Re: Piece/square table challenge
Hi Evert,
May I ask:
- What were the t-stats on each coefficient?
- Did you have a constants in the model (which I think you need) or did you force through origin
Steve
I'm not sure negative coefficients make sense in this context. A negative coefficient is saying the opposite variation in score is appropriate - which I don't think makes sense.Evert wrote:(...)
with coefficients -1.26987, 9.64933, -8.48597, 4.45139 and 0.0887156. (...)
May I ask:
- What were the t-stats on each coefficient?
- Did you have a constants in the model (which I think you need) or did you force through origin
Steve
http://www.chessprogramming.net - Juggernaut & Maverick Chess Engine
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Re: Piece/square table challenge
It does, but it's a bit ugly.Steve Maughan wrote: I'm not sure negative coefficients make sense in this context. A negative coefficient is saying the opposite variation in score is appropriate - which I don't think makes sense.
Let's look at the third coefficient first, which multiplies the tropism table. The sign is due to the way the tropism table works: it records the number of steps required to reach a particular square. That means the value is high for squares that are far away from the target - but this is the opposite of what you want, because you really want squares that are "close" to give you the largest bonus. So really, the table should be transformed into (max_value_in_table - table), but then the first of these is a constant that can be taken out and you end up just subtracting the table. So in a sense, the only value that really makes sense is a negative value (otherwise a piece is better placed if it is far away from the king; could be of course, but if that's what we find we can scrap the idea).
The negative value for the first coefficient looks more suspicious (because at face-value it says that it's better for the knight to be way from the centre), but you have to remember that the fourth table (which is based on mobility scores) is also a centralisation table and it's really the combination of these two that matters. The relative difference between coefficient 1 and 4 more reflects what exactly the centralisation PST should look like than anything else.
If you look at the final table you'll see that it still favours centralisation.
I actually don't have any real data on the quality of the fit, since it was very trial-and-error and ad-hoc. I do have the (unreduced) chi-squared, which is something like 36000 (ie, poor). I don't think getting a very good fit is all that important, actually, because in the games that the empirical table is based on the king is not glued to g8, but gets to wander around and there may be other targets that affect where you prefer to place your pieces. The main thing I take away from it at this stage is the ratio of the asymmetric part to the symmetric part (~8.4/4.4) which tells me something about how important it is to get the piece close to the enemy king, relative to the centralisation. Actually, the advancement table also looks like it is more important than I thought (hoped) it would be, which annoys me a little.- What were the t-stats on each coefficient?
- Did you have a constants in the model (which I think you need) or did you force through origin
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Re: Piece/square table challenge
Evert,
OK - certainly for tropism the negative coefficient is fine.
This should be a straightforward linear regression. If I have time I'll do it.
Steve
OK - certainly for tropism the negative coefficient is fine.
This should be a straightforward linear regression. If I have time I'll do it.
Steve
http://www.chessprogramming.net - Juggernaut & Maverick Chess Engine
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Re: Piece/square table challenge
Code: Select all
Program Elo + - Games Score Av.Op. Draws
1 Rodent 1.3 (build adam) : 2082 11 11 3642 64.9 % 1975 18.8 %
2 Rodent 1.3 (build pawel) : 2060 10 10 3641 61.4 % 1979 22.3 %
3 Rodent 1.3 (build lyudmil) : 2021 12 12 2560 48.6 % 2031 21.8 %
4 Rodent 1.3 (build mikko+) : 2005 11 11 3082 50.1 % 2004 22.1 %
5 Rodent 1.3 (build pio) : 2001 15 15 1545 48.7 % 2010 23.9 %
6 Rodent 1.3 (build ufo) : 2000 9 9 4069 51.6 % 1990 24.9 %
7 Rodent 1.3 (build lucas) : 1966 13 13 2026 42.1 % 2021 24.7 %
8 Rodent 1.3 (build ERROR) : 1935 14 14 2036 36.9 % 2029 22.0 %
9 Rodent 1.3 (build daniel) : 1836 15 15 2063 23.7 % 2039 17.5 %
Pawel Koziol
http://www.pkoziol.cal24.pl/rodent/rodent.htm
http://www.pkoziol.cal24.pl/rodent/rodent.htm
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Re: Piece/square table challenge
I think it brings up again an idea to use, at least, king sides flags as additional dimension. See: http://www.talkchess.com/forum/viewtopic.php?t=50294Uri Blass wrote:I totally dislike adam's set because it is not symmetric to files and it can be interesting if you can test a symmetric version of his set by simply replacing every 2 numbers by the average of them so if knight at b3 and knight at g3 have different values you replace the values simply by the average.
I wonder if this version cannot score even better because I doubt the idea of attacking the opponent king when you even do not know where it is can be good.
In most cases the king go to the king side with symmetric evaluation and still attacking in that side may change the decision of the opponent in part of the cases because the opponent can see for tactical reasons in some cases that it is better not to go to the king side.
I also think that attacking in the queen side can also be effective even the opponent castle short because there are other targets to attack in a chess game and not only the opponent king.
The Force Be With You!
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- Full name: Vladimir Medvedev
Re: Piece/square table challenge
Here are GreKo values. They are very simple. Doubt they can provide any sort of strong play, but nevertheless...
Pawn (mg and eg):
Knight (mg and eg):
Bishop (mg and eg):
Rook (mg and eg):
King (mg):
King (eg):
Pawn (mg and eg):
Code: Select all
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 10, 10, 0, 0, 0,
0, 0, 5, 10, 10, 5, 0, 0,
0, 0, 5, 10, 10, 5, 0, 0,
0, 0, 5, 5, 5, 5, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
Code: Select all
-10, -6, -3, 0, 0, -3, -6, -10,
-6, -3, 0, 3, 3, 0, -3, -6,
-3, 0, 3, 6, 6, 3, 0, -3,
0, 3, 6, 10, 10, 6, 3, 0,
0, 3, 6, 10, 10, 6, 3, 0,
-3, 0, 3, 6, 6, 3, 0, -3,
-6, -3, 0, 3, 3, 0, -3, -6,
-10, -6, -3, 0, 0, -3, -6, -10
Code: Select all
-10, -6, -3, 0, 0, -3, -6, -10,
-6, -3, 0, 3, 3, 0, -3, -6,
-3, 0, 3, 6, 6, 3, 0, -3,
0, 3, 6, 10, 10, 6, 3, 0,
0, 3, 6, 10, 10, 6, 3, 0,
-3, 0, 3, 6, 6, 3, 0, -3,
-6, -3, 0, 3, 3, 0, -3, -6,
-10, -6, -3, 0, 0, -3, -6, -10
Code: Select all
0, 0, 0, 0, 0, 0, 0, 0,
20, 20, 20, 20, 20, 20, 20, 20,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
Code: Select all
-40, -40, -40, -40, -40, -40, -40, -40,
-40, -40, -40, -40, -40, -40, -40, -40,
-40, -40, -40, -40, -40, -40, -40, -40,
-40, -40, -40, -40, -40, -40, -40, -40,
-40, -40, -40, -40, -40, -40, -40, -40,
-40, -40, -40, -40, -40, -40, -40, -40,
-20, -20, -20, -20, -20, -20, -20, -20,
-10, 0, 0, -10, 0, -10, 0, -10
Code: Select all
-40, -26, -13, 0, 0, -13, -26, -40,
-26, -13, 0, 13, 13, 0, -13, -26,
-13, 0, 13, 26, 26, 13, 0, -13,
0, 13, 26, 40, 40, 26, 13, 0,
0, 13, 26, 40, 40, 26, 13, 0,
-13, 0, 13, 26, 26, 13, 0, -13,
-26, -13, 0, 13, 13, 0, -13, -26,
-40, -26, -13, 0, 0, -13, -26, -40
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Re: Piece/square table challenge
Can a chess engine with pesto evaluation beat 2000+ player?