Author: Robert Hyatt
Date: 19:51:22 12/07/99
Go up one level in this thread
On December 07, 1999 at 22:20:43, Vincent Diepeveen wrote:
>On December 07, 1999 at 14:36:50, Robert Hyatt wrote:
>
>>On December 07, 1999 at 09:17:07, Vincent Diepeveen wrote:
>>
>>>On December 06, 1999 at 08:46:09, Robert Hyatt wrote:
>>>
>>>>On December 06, 1999 at 02:54:30, Harald Faber wrote:
>>>>
>>>>>On December 05, 1999 at 22:35:23, Michael Fuhrmann wrote:
>>>>>
>>>>>>Bob Hyatt stated in a recent post that all chess programs have "absolutely
>>>>>>glaring holes." What are the specific weaknesses of some of the top programs.
>>>>>
>>>>>In most cases it is their own king safety.
>>>>
>>>>
>>>>That is certainly a big one.
>>>
>>>should specify by program though. not all
>>>gms are the same, not all programs are the same.
>>>
>>>>Another is over-rating the attacking chances relative to the opponent's
>>>>king safety. IE many programs think that after Bxg3 hxg3 that white's
>>>>king is very unsafe, when in reality, it is not with a doubled pawn at
>>>>g3.
>>>
>>>Right, this problem is extreme by
>>>the following programs/systems:
>>> - deep thought
>>> - deep blue
>>> - deepviolet (at the iccserver, softwareversion PII-400 getting 22k nps)
>>>
>>>Not even gnuchess is having the f2g2g3 pattern detection as bad implemented
>>>as the above 3.
>>>
>>>>Passed pawns. Many over-value these, to the point that they will create an
>>>>advanced one that becomes lost laster. Others have no clue about the advantage
>>>
>>>Yes crafty even says 2 pawns at the third row are worth a rook
>>>not taking into account the king.
>>
>>You may not be able to read a bitmap program properly. Two connected passers
>>on the 6th are _not_ worth a rook, _unless_ the king is far enough away that
>>it can't reach either promoting square. And neither of the pawns can be
>>blockaded...
>
>Wrong, white to move all pawns on 3d rank, so if we only make Rb7 here then
>all pawns are inside quadrant of white king or can be stopped by rook.
>just the BIG luck here for black is that there is a pawn on e3, otherwise
>ke3 wins here for black bigtime.
>
If you remove the pawn on e3, crafty doesn't take on b2. I just loaded
the position and tried it. It simply plays Ke6 now with the e3 pawn missing.
>Black(1): white
>White(1): d
>
> +---+---+---+---+---+---+---+---+
> 8 | | | | | | | | |
> +---+---+---+---+---+---+---+---+
> 7 | | | | | | | | *P|
> +---+---+---+---+---+---+---+---+
> 6 | | | | | | *K| | |
> +---+---+---+---+---+---+---+---+
> 5 | | | | | | *P| | |
> +---+---+---+---+---+---+---+---+
> 4 | *P| | | | | P | | |
> +---+---+---+---+---+---+---+---+
> 3 | P | | *P| *P| P | K | | |
> +---+---+---+---+---+---+---+---+
> 2 | | | | | | | | P |
> +---+---+---+---+---+---+---+---+
> 1 | | R | | | | | | |
> +---+---+---+---+---+---+---+---+
> a b c d e f g h
>
>White(1): anal
>Analyze Mode: type "exit" to terminate.
>end-game phase
> clearing hash tables
> time surplus 0.00 time limit 30.00 (3:00)
> s depth time score variation (1)
> 1 0.00 -2.49 1. Rb7
> 1-> 0.03 -2.49 1. Rb7
> 2 0.06 -- 1. Rb7
> 2 0.08 -2.97 1. Rb7 h5
> 2 0.11 -2.44 1. Rb6+ Kf7 2. Rb7+ Kg6
> 2 0.14 ++ 1. e4!!
> 2 0.17 -1.79 1. e4 h5 2. exf5
> 2 0.20 0.92 1. Rd1 c2 2. Rc1
> 2 0.22 0.93 1. Rc1 d2 2. Rd1
> 2-> 0.26 0.93 1. Rc1 d2 2. Rd1
> 3 0.28 -- 1. Rc1
> 3 0.31 -2.91 1. Rc1 d2 2. Rd1 c2 3. Rxd2 c1=Q
> 3 0.34 -2.13 1. Rb6+ Ke7 2. Rb7+ Kd6 3. Rxh7
> 3 0.37 -1.56 1. e4 fxe4+ 2. Ke3 Kf5
> 3-> 0.41 -1.56 1. e4 fxe4+ 2. Ke3 Kf5
> 4 0.47 -- 1. e4
> 4 0.52 -2.04 1. e4 c2 2. e5+ Ke6 3. Rb6+ Ke7 4.
> Rd6
> 4 0.58 ++ 1. Rb6+!!
> 4-> 0.65 -1.17 1. Rb6+
> 5 0.72 -- 1. Rb6+
> 5 0.89 -2.23 1. Rb6+ Ke7 2. Rb7+ Kd8 3. Rxh7 c2
> 4. Rh8+ Kd7 5. Rc8
> 5-> 1.20 -2.23 1. Rb6+ Ke7 2. Rb7+ Kd8 3. Rxh7 c2
> 4. Rh8+ Kd7 5. Rc8
> 6 1.78 -2.03 1. Rb6+ Ke7 2. Rb7+ Kd6 3. Ra7 c2 4.
> Rxa4 Ke6 5. Rd4
> 6 1.97 -1.94 1. e4 c2 2. e5+ Ke7 3. Rb7+ Kd8 4.
> Rb6 Kc7 5. Rd6
> 6-> 2.24 -1.94 1. e4 c2 2. e5+ Ke7 3. Rb7+ Kd8 4.
> Rb6 Kc7 5. Rd6
> 7 2.64 -1.93 1. e4 c2 2. e5+ Ke7 3. Rb7+ Ke6 4.
> Rb6+ <HT>
> 7-> 3.36 -1.93 1. e4 c2 2. e5+ Ke7 3. Rb7+ Ke6 4.
> Rb6+ <HT>
> 8 4.35 -2.09 1. e4 c2 2. e5+ Ke7 3. Rb7+ Kd8 4.
> Rb6 c1=Q 5. Rd6+ Ke7 6. Rxd3 Ke6
> 8 5.69 -1.74 1. Rb6+ Ke7 2. Rb7+ Ke6 3. Rb6+ Kf7
> 4. Rb7+ Ke8 5. Rxh7 c2 6. Rc7 d2 7.
> Rc8+ Ke7 8. Rxc2 d1=Q+
> 8-> 6.50 -1.74 1. Rb6+ Ke7 2. Rb7+ Ke6 3. Rb6+ Kf7
> 4. Rb7+ Ke8 5. Rxh7 c2 6. Rc7 d2 7.
> Rc8+ Ke7 8. Rxc2 d1=Q+
>
>
>crafty is so happy to play Rxb2 because it finds a position with
>king in quadrant winning for black though it's a rook down!
>
>So that's 8 pawns if i'm not mistaken. 4 pawns bonus each pawn
absolutely not. The total score is about 4 pawns max. If you look at
the code:
if (TotalWhitePieces < queen_v &&
!(SetMask(square1-8)&WhitePieces) &&
!(SetMask(square2-8)&WhitePieces)) {
score-=2*PAWN_CONNECTED_PASSED_6TH;
if ((TotalWhitePieces <= rook_v) &&
(!(WhiteKing&black_pawn_race_btm[square1]) ||
!(WhiteKing&black_pawn_race_btm[square2])))
score-=6*PAWN_CONNECTED_PASSED_6TH;
}
If we get to that we have two connected passers on the
6th rank.
I require that the opponent have < than a queen, which normally
means a rook or a single piece, but possibly two pieces. And the
two pawns can not be blockaded. If that is true, the first
bonus is folded in (PAWN_CONNECTED_PASSED_6TH == .5) wo
we get 1 pawn for that. If the opponent has a rook or less, and the king
can't get to the queening square for either pawn, then we add in
3 more. Total=4, _not_ 8. And I don't do this for each pawn,
but for each _pair_ of connected passers...
>
>So WITHOUT the pawn on e3 it might at 1 ply be very happy here with
>white?
>
>SURE!!!!!
>
>-0.76 even though it's a full rook down!
I get +4 for white here:
11 8.12 4.07 2. Rxb2 Ke6 3. Ke3 Kd5 4. Rb5+ Kc6
5. Rxf5 Kb6 6. Kd2 h5 7. Kc3 Kc6 8.
Kxc4
11-> 8.17 4.07 2. Rxb2 Ke6 3. Ke3 Kd5 4. Rb5+ Kc6
5. Rxf5 Kb6 6. Kd2 h5 7. Kc3 Kc6 8.
Kxc4
12 13.58 4.35 2. Rxb2 Ke6 3. Ke3 Kd5 4. Rb5+ Kc6
5. Rxf5 Kb6 6. Rd5 Kc6 7. Kd4 h5 8.
Kxc4
12-> 13.76 4.35 2. Rxb2 Ke6 3. Ke3 Kd5 4. Rb5+ Kc6
5. Rxf5 Kb6 6. Rd5 Kc6 7. Kd4 h5 8.
Kxc4
This is after I remove the pawn on e3 and then lay
Rxb2 for black. I don't know what you are talking about here.
>
>
>White(1): d
>
> +---+---+---+---+---+---+---+---+
> 8 | | | | | | | | |
> +---+---+---+---+---+---+---+---+
> 7 | | | | | | | | *P|
> +---+---+---+---+---+---+---+---+
> 6 | | | | | | *K| | |
> +---+---+---+---+---+---+---+---+
> 5 | | | | | | *P| | |
> +---+---+---+---+---+---+---+---+
> 4 | *P| | | | | P | | |
> +---+---+---+---+---+---+---+---+
> 3 | P | | *P| *P| | K | | |
> +---+---+---+---+---+---+---+---+
> 2 | | | | | | | | P |
> +---+---+---+---+---+---+---+---+
> 1 | | R | | | | | | |
> +---+---+---+---+---+---+---+---+
> a b c d e f g h
>
>White(1): an
>Analyze Mode: type "exit" to terminate.
>end-game phase
> clearing hash tables
> time surplus 0.00 time limit 30.00 (3:00) [easy move]
> s depth time score variation (1)
> 1 0.00 -0.76 1. Ke3
> 1-> 0.06 -0.76 1. Ke3
> 2 0.08 ++ 1. Ke3!!
> 2 0.11 0.00 1. Ke3 c2 2. Rc1
> 2-> 0.14 0.00 1. Ke3 c2 2. Rc1
> 3 0.17 -0.32 1. Ke3 d2 2. Rd1 c2 3. Kxd2 cxd1=Q+
> 4. Kxd1
> 3-> 0.24 -0.32 1. Ke3 d2 2. Rd1 c2 3. Kxd2 cxd1=Q+
> 4. Kxd1
> 4 0.30 ++ 1. Ke3!!
> 4 0.33 2.85 1. Ke3 d2 2. Kd3 Ke6 3. Kxc3
> 4-> 0.40 2.85 1. Ke3 d2 2. Kd3 Ke6 3. Kxc3
> 5 0.44 ++ 1. Ke3!!
> 5 0.50 4.87 1. Ke3 d2 2. Kd3 Ke6 3. Kxc3 h5 4.
> Kxd2
> 5-> 0.66 4.87 1. Ke3 d2 2. Kd3 Ke6 3. Kxc3 h5 4.
> Kxd2
> 6 0.80 4.78 1. Ke3 Ke6 2. Kxd3 Kd5 3. Kxc3 Ke4
> 6-> 1.10 4.78 1. Ke3 Ke6 2. Kxd3 Kd5 3. Kxc3 Ke4
> 7 1.53 4.78 1. Ke3 d2 2. Kd3 Ke6 3. Kxc3 Kd5 4.
> Kxd2 Ke4
> 7-> 2.07 4.78 1. Ke3 d2 2. Kd3 Ke6 3. Kxc3 Kd5 4.
> Kxd2 Ke4
>quit 8 2.12 1/20 1. Ke3
>White(1): quit
>execution complete.
>
>K:\chess\crafty>
>
>So now the ultimate test: let's get away the e3 pawn at position 2
>of the WAC test. Taking on b2 is now simply losing a rook. Does crafty
>consider this?
>
>SURE!!!!
>
>Black(1): d
>
> +---+---+---+---+---+---+---+---+
> 8 | | | | | | | | |
> +---+---+---+---+---+---+---+---+
> 7 | | | | | | | | *P|
> +---+---+---+---+---+---+---+---+
> 6 | | | | | | *K| | |
> +---+---+---+---+---+---+---+---+
> 5 | | | | | | *P| | |
> +---+---+---+---+---+---+---+---+
> 4 | *P| | *P| | | P | | |
> +---+---+---+---+---+---+---+---+
> 3 | P | *R| | *P| | K | | |
> +---+---+---+---+---+---+---+---+
> 2 | | P | | R | | | | P |
> +---+---+---+---+---+---+---+---+
> 1 | | | | | | | | |
> +---+---+---+---+---+---+---+---+
> a b c d e f g h
>
>Black(1): anal
>Analyze Mode: type "exit" to terminate.
>end-game phase
> clearing hash tables
> time surplus 0.00 time limit 30.00 (3:00)
> s depth time score variation (1)
> 1 0.00 2.28 1. ... Ke6
> 1-> 0.03 2.28 1. ... Ke6
> 2 0.06 2.18 1. ... Ke6 2. Ke3
> 2-> 0.09 2.18 1. ... Ke6 2. Ke3
> 3 0.12 2.28 1. ... Ke6 2. Ke3 Kd5
> 3 0.15 ++ 1. ... Rxb2!!
> 3 0.17 3.81 1. ... Rxb2 2. Rxb2 c3
> 3-> 0.21 3.81 1. ... Rxb2 2. Rxb2 c3
> 4 0.23 -- 1. ... Rxb2
> 4 0.26 3.44 1. ... Rxb2 2. Rxb2 c3 3. Rd2 cxd2
> 4-> 0.29 3.44 1. ... Rxb2 2. Rxb2 c3 3. Rd2 cxd2
> 5 0.32 -- 1. ... Rxb2
> 5 0.35 0.71 1. ... Rxb2 2. Rxb2 c3 3. Rb6+ Ke7
> 4. Ke3
>
>
>
>
Here is _real_ output. I have no idea how you are setting this up, but my
version does _not_ play Rxb2 with the e3 pawn missing:
+---+---+---+---+---+---+---+---+
8 | | | | | | | | |
+---+---+---+---+---+---+---+---+
7 | | | | | | | | *P|
+---+---+---+---+---+---+---+---+
6 | | | | | | *K| | |
+---+---+---+---+---+---+---+---+
5 | | | | | | *P| | |
+---+---+---+---+---+---+---+---+
4 | *P| | *P| | | P | | |
+---+---+---+---+---+---+---+---+
3 | P | *R| | *P| | K | | |
+---+---+---+---+---+---+---+---+
2 | | P | | R | | | | P |
+---+---+---+---+---+---+---+---+
1 | | | | | | | | |
+---+---+---+---+---+---+---+---+
Is the starting position. I only get c3 and Ke6 here at any depth. I have
not tried older versions and don't know whether this might be broken or not.
I'm not unhappy with it however, as to this point in time I have not seen it
lose a game, and I have seen it win plenty...
>
>
>
>>
>>
>>
>>
>>>
>>>Patzer seems giving a pawn at the 6th rank +3.0 or something anyway.
>>>
>>>Nimzo is very happy too with passed pawns.
>>>
>>>Basically it's tough to detect how well pawns are stopped, i bet all programs
>>>have to some extend big problems with this as the evaluation is so dependant
>>>upon just a few terms here. Every term is having a big impact on the evaluation
>>>of the position.
>>>
>>>>of an outside (or distant) passed pawn. An ancillary point here is that even
>>>>if a program recognizes a passed pawn as good (outside passed pawn) many don't
>>>>recognize a 'distant majority' which is essentially the same thing. I have
>>>>seen more than one program trade into a K+P vs K+P (multiple p's on both
>>>>sides) ending that was dead lost, even though they might have been a pawn
>>>>up or have a more advanced passer.
>>>
>>>Right, this might be a problem that will remain long time a problem.
>>>there are many factors and reevaluations
>>>to consider before you can apply to such a far
>>>majority a winning bonus.
>>>
>>>>Some value a rook on the 7th too highly, particularly after all the pawns have
>>>>advanced and the king is centralized. A rook on the 7th there isn't doing
>>>>anything, yet more than one program is very happy with it.
>>>
>>>a problem in diep is it wants to centralize king in endgame always.
>>>usual that's good but sometimes...
>>>
>>>>Some (including older versions of crafty) value connected passed pawns more
>>>>valuable than two isolated passed pawns... This is wrong in king and pawn (only)
>>>>endings...
>>>>
>>>>The list goes on and on...
>>>
>>>Right, however the biggest problem are closed positions.
>>>The problem with closed positions is that the rules are sometimes the
>>>opposite of normal positions.
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