Sacrificing a Knight while a pawn down...

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GothicChessInventor

Sacrificing a Knight while a pawn down...

Post by GothicChessInventor »

Image

From the 2007 Computer Championship, not many programs would see 18. Nh5+!!

http://www.gothicchess.com/javagames/db ... 1/game.htm
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Roman Hartmann
Posts: 295
Joined: Wed Mar 08, 2006 8:29 pm

Re: Sacrificing a Knight while a pawn down...

Post by Roman Hartmann »

Most engines would probably just crash :D

Roman
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Uri Blass
Posts: 10100
Joined: Thu Mar 09, 2006 12:37 am
Location: Tel-Aviv Israel

Re: Sacrificing a Knight while a pawn down...

Post by Uri Blass »

I guess this is a question of time
Based on the game smirf got only depth 9 in the previous move and after Nh5+ understood that it is losing the game.

I think that smirf is simply outsearched.

Bd7 (09.32) -0.238
18.Nh5+ gxh5 (12.00) -2.998
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hgm
Posts: 27700
Joined: Fri Mar 10, 2006 10:06 am
Location: Amsterdam
Full name: H G Muller

Re: Sacrificing a Knight while a pawn down...

Post by hgm »

Everything is a question of time. But you should realize that the branching factor of Gothic Chess is much larger than that of FIDE Chess, and that 9 ply is really quite deep. Fairy-Max needs 15 minutes to get to 8 ply here, (OK, that is on a 1GHz Athlon XP...), and then still does not see the Knight move.
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GothicChessInventor

Re: Sacrificing a Knight while a pawn down...

Post by GothicChessInventor »

Here is the partial log from Vortex's search from that game:

http://www.gothicchess.com/Vortex_SMIRF_partial_log.txt

It saw the sacrifice in less than one second starting at ply 5 once it entered the position. The new Vortex "extended extensions" and King Safety code kicked it to produce that move.

Code: Select all

=====================
=                   =
= GOTHIC VORTEX LOG =
=                   =
=====================

Version 2.2.3 


                     WHITE TO MOVE

       +---+---+---+---+---+---+---+---+---+---+
    8  |<R>|   |   |<Q>|<C>|   |   |   |   |<R>|
       +---+---+---+---+---+---+---+---+---+---+
    7  |<P>|<P>|   |<B>|<P>|<P>|<K>|<P>|<P>|   |
       +---+---+---+---+---+---+---+---+---+---+
    6  |   |   |<N>|<P>|   |   |<P>|<N>|   |   |
       +---+---+---+---+---+---+---+---+---+---+
    5  |   |   |   |   |   |   |-B-|   |   |<P>|
       +---+---+---+---+---+---+---+---+---+---+
    4  |   |   |   |   |   |-N-|   |   |   |-C-|
       +---+---+---+---+---+---+---+---+---+---+
    3  |   |   |   |   |   |   |-P-|   |   |   |
       +---+---+---+---+---+---+---+---+---+---+
    2  |-P-|   |-P-|-Q-|-P-|-P-|-B-|-P-|-P-|-P-|
       +---+---+---+---+---+---+---+---+---+---+
    1  |-R-|   |   |   |   |   |   |-R-|-K-|   |
       +---+---+---+---+---+---+---+---+---+---+
         a   b   c   d   e   f   g   h   i   j

TotalWhitePieces    = 53 pawns
TotalWhitePawns     = 8 pawns
TotalWhiteMaterial  = 61 pawns

TotalBlackPieces    = 52 pawns
TotalBlackPawns     = 9 pawns
TotalBlackMaterial  = 61 pawns

Material Score      = -25 &#40;1 pawn = 100&#41;


*********************************************
*                                           *
* SEARCH EXTENSION/EVALUATION FUNCTION DATA *
*                                           *
*********************************************


@@@@@@@@@@@@@@@@@@@@@
@@@@@ CONSTANTS @@@@@
@@@@@@@@@@@@@@@@@@@@@

TOTAL_MATERIAL_AT_START...................... = 156 pawns
MATERIAL_FOR_FAST_EXTENSIONS................. = 78 pawns
MATERIAL_FOR_BLITZ_EVALUATION................ = 39 pawns
MATERIAL_DIFFERENCE_FOR_BLITZ_EVALUATION..... = 799 &#40;1 pawn = 100&#41;

QUICK_EVAL_CUTOFF............................ = 550 &#40;1 pawn = 100&#41;
GREATEST_POSITIONAL_SCORE.................... = 700 &#40;1 pawn = 100&#41;

@@@@@@@@@@@@@@@@@@@@@
@@@@@ VARIABLES @@@@@
@@@@@@@@@@@@@@@@@@@@@

GameHistory.total_material&#91;34&#93;............... = 122 pawns
GameHistory.material_difference&#91;34&#93;.......... = 0 &#40;1 pawn = 100&#41;

@@@@@@@@@@@@@@@@@@
@@@@@ MACROS @@@@@
@@@@@@@@@@@@@@@@@@

#define LeanMeanFastEvaluationMode&#40;x&#41; (&#40;x&#41; <= MATERIAL_FOR_FAST_EXTENSIONS&#41;
#define ExecuteBlitzEvaluation&#40;x,y&#41; ((&#40;x&#41; <= MATERIAL_FOR_BLITZ_EVALUATION&#41; || (&#40;y&#41; > MATERIAL_DIFFERENCE_FOR_BLITZ_EVALUATION&#41;)


@@@@@@@@@@@@@@@@@@@@@@@
@@@@@ SEARCH TYPE @@@@@
@@@@@@@@@@@@@@@@@@@@@@@

LimitExtensions calls DeepExtensions.

Search returns MATERIAL + POSITIONAL + TROPISM terms in slower, most accurate mode.

*********************
*                   *
* PIECE DEVELOPMENT *
*                   *
*********************


@@@@@@@@@@@@@@@@@@@@@
@@@@@ VARIABLES @@@@@
@@@@@@@@@@@@@@@@@@@@@

knight_undeveloped&#91;k_white&#93;     = 0
bishop_undeveloped&#91;k_white&#93;     = 0
archbishop_undeveloped&#91;k_white&#93; = 0
chancellor_undeveloped&#91;k_white&#93; = 0
queen_undeveloped&#91;k_white&#93;      = 0

knight_undeveloped&#91;k_black&#93;     = 0
bishop_undeveloped&#91;k_black&#93;     = 0
archbishop_undeveloped&#91;k_black&#93; = 0
chancellor_undeveloped&#91;k_black&#93; = 1
queen_undeveloped&#91;k_black&#93;      = 1

@@@@@@@@@@@@@@@@@@@@@
@@@@@ CONSTANTS @@@@@
@@@@@@@@@@@@@@@@@@@@@

(----- BONUSES -----)

PROPER_ARCHBISHOP_DEPLOYMENT .................................. = 15
PROPER_CHANCELLOR_DEPLOYMENT .................................. = 10

BONUS_FOR_GETTING_ONE_BISHOP_IN_PLAY .......................... = 2
BASELINE_ALL_KNIGHTS_DEVELOPED_BONUS .......................... = 10
BASELINE_ALL_BISHOPS_DEVELOPED_BONUS .......................... = 10

BONUS_PER_KNIGHT_DEVELOPED_THAT_YOUR_OPPONENT_HAS_NOT_DEVELOPED = 6
BONUS_PER_BISHOP_DEVELOPED_THAT_YOUR_OPPONENT_HAS_NOT_DEVELOPED = 4

(---- penalties ----)

QUEEN_BEFORE_KNIGHT_PENALTY ................................... = 25
CHANCELLOR_BEFORE_KNIGHT_PENALTY .............................. = 25
ARCHBISHOP_BEFORE_KNIGHT_PENALTY .............................. = 15

(----- EVALUATION -----)

WHITE REWARD = 10 for getting all knights developed + bonus if opponent has undeveloped knights.
WHITE REWARD = 10 for getting all Bishops developed. No additional merit if opponent is lagging behind.
WHITE REWARD = 15 for properly developing the Archbishop after the minors are in play.
WHITE REWARD = 10 for properly developing the Chancellor after the Archbishop was in play.


WHITE DEVELOPMENT BONUS = 45

BLACK REWARD &#40;negative is better&#41; = -10 for getting all knights developed + bonus if opponent has undeveloped knights.
BLACK REWARD = -10 for getting all Bishops developed. No additional merit if opponent is lagging behind.
BLACK REWARD &#40;negative is better&#41; = -15 for properly developing the Archbishop after the minors are in play.

BLACK DEVELOPMENT BONUS = -35



@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@ WHITE DEVELOPMENT SCORE @@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

45

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@ BLACK DEVELOPMENT SCORE @@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

-35

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@ NET SCORE RETURNED @@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

10

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@                    @@@@@
@@@@@ KING SAFETY MODULE @@@@@
@@@@@                    @@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

@@@@@@@@@@@@@@@@@@@@@
@@@@@ CONSTANTS @@@@@
@@@@@@@@@@@@@@@@@@@@@

CASTLE_BONUS                  = 55
LOST_KINGSIDE_PRIVILEDGE      = 50
LOST_QUEENSIDE_PRIVILEDGE     = 25
OVERLY_DISPLACED_KING_PENALTY = 180

CLASSIC_FIANCHETTO_INDEX                  = 21
HYPERMODERN_FORTRESS_CANDIDATE_INDEX      = 2
EQUIVALENT_INDEX_IF_FORTRESS_SATISFACTORY = 17

@@@@@@@@@@@@@@@@@@@@@
@@@@@ VARIABLES @@@@@
@@@@@@@@@@@@@@@@@@@@@

WhiteKingSQ = 8
BlackKingSQ = 66

Rank&#40;WhiteKingSQ = 0
Rank&#40;BlackKingSQ = 6
File&#40;WhiteKingSQ = 8
File&#40;BlackKingSQ = 6


@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@ PAWN SHELTER @@@@@
@@@@@@@@@@@@@@@@@@@@@@@@

White King Pawn Shelter Index= 7
- - - - - - - - - -      70 
- - - - - - - - - -      60 
- - - - - - - - - -      50 
- - - - - - - - - -      40 
- - - - - - - - - -      30 
- - - - - - - - - -      20 
- - - - - - - X X X      10 
- - - - - - - - O -       0 



Flopped Black King Pawn Shelter Index = 2
&#40;black pretends to be in the equivalent white position for the above&#41;
- - - - - - - - - -      70 
- - - - - - - - - -      60 
- - - - - - - - - -      50 
- - - - - - - - - -      40 
- - - - - - - - - -      30 
- - - - - - X - - -      20 
- - - - - - O - - -      10 
- - - - - - - - - -       0 



(----- EVALUATION -----)


******* WHITE KING SAFETY SHELTER SCORE = 72 *******
&#40;computed from g_white_king_pawn_shelter_merit&#91;8&#93;&#91;7&#93;)

******* BLACK KING SAFETY SHELTER SCORE = 26 *******
&#40;computed from g_white_king_pawn_shelter_merit&#91;16&#93;&#91;17&#93;)



******* FINAL KING SAFETY SCORE = 98 &#40;positive is better&#41; *******

**********************
*                    *
*   MOVE GENERATOR   *
*                    *
**********************


WHITE KNIGHT PRE-EVAL adding 4
WHITE KNIGHT TROPISM  adding 30 for reaching square 35

BLACK KNIGHT PRE-EVAL adding -8
BLACK KNIGHT TROPISM  adding 0 for reaching square 52

BLACK KNIGHT PRE-EVAL adding -10
BLACK KNIGHT TROPISM  adding 0 for reaching square 57

WHITE BISHOP PRE-EVAL adding 8
WHITE BISHOP mobility adding 27
WHITE BISHOP TROPISM  adding 0 for reaching square 16

WHITE BISHOP PRE-EVAL adding 0
WHITE BISHOP mobility adding 21
WHITE BISHOP TROPISM  adding 20 for reaching square 46

BLACK BISHOP PRE-EVAL adding -6 for reaching square 63
BLACK BISHOP mobility adding -24
BLACK BISHOP TROPISM  adding 0 for reaching square 63

WHITE CHANCELLOR PRE-EVAL adding -12
WHITE CHANCELLOR TROPISM  adding 35 for reaching square 39

BLACK CHANCELLOR PRE-EVAL adding 15
BLACK CHANCELLOR TROPISM  adding 0 for reaching square 74

WHITE QUEEN PRE-EVAL adding 8
WHITE QUEEN TROPISM  adding 0 for reaching square 13

BLACK QUEEN PRE-EVAL adding 0
BLACK QUEEN TROPISM  adding 0 for reaching square 73

WHITE ROOK PRE-EVAL adding 0
WHITE ROOK TROPISM  adding 0 for reaching square 0

WHITE ROOK PRE-EVAL adding 0
WHITE ROOK TROPISM  adding 0 for reaching square 7

BLACK ROOK PRE-EVAL adding 0
BLACK ROOK TROPISM  adding 0 for reaching square 70

BLACK ROOK PRE-EVAL adding 0
BLACK ROOK TROPISM  adding 0 for reaching square 79

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$                             $$$
$$$     FINAL POSITION SCORE    $$$
$$$                             $$$
$$$     00000000000000000140    $$$
$$$                             $$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$


Ply&#58; 1-2 &#40;start&#41;  Time 0&#58;00    Eval&#58; 181  Nodes&#58; 207  Nodes/Sec&#58; 348300   Branching&#58; 0.00
Line&#58;  Qd2d5

Ply&#58; 1-4 &#40;ended&#41;  Time 0&#58;00    Eval&#58; 181  Nodes&#58; 287  Nodes/Sec&#58; 312455   Branching&#58; 287.00
Line&#58;  Qd2d5

Ply&#58; 2-4 &#40;start&#41;  Time 0&#58;00    Eval&#58; 21  Nodes&#58; 344  Nodes/Sec&#58; 312455   Branching&#58; 287.00
Line&#58;  Qd2d5 Kg7h8

Ply&#58; 2-6 &#40;start&#41;  Time 0&#58;00    Eval&#58; 89  Nodes&#58; 451  Nodes/Sec&#58; 312455   Branching&#58; 287.00
Line&#58;  Bg5xh6+ i7xh6 Bg2xj5

Ply&#58; 2-8 &#40;start&#41;  Time 0&#58;00    Eval&#58; 124  Nodes&#58; 1115  Nodes/Sec&#58; 312455   Branching&#58; 287.00
Line&#58;  Nf4d5 f7f6

Ply&#58; 2-8 &#40;ended&#41;  Time 0&#58;00    Eval&#58; 124  Nodes&#58; 1267  Nodes/Sec&#58; 312455   Branching&#58; 4.41
Line&#58;  Nf4d5 f7f6

Ply&#58; 3-10 &#40;start&#41;  Time 0&#58;00    Eval&#58; 128  Nodes&#58; 1552  Nodes/Sec&#58; 312455   Branching&#58; 4.41
Line&#58;  Nf4d5 f7f6 Qd2c3

Ply&#58; 3-10 &#40;ended&#41;  Time 0&#58;00    Eval&#58; 128  Nodes&#58; 9057  Nodes/Sec&#58; 312455   Branching&#58; 7.14
Line&#58;  Nf4d5 f7f6 Qd2c3

Ply&#58; 4-10 &#40;start&#41;  Time 0&#58;00    Eval&#58; 115  Nodes&#58; 10148  Nodes/Sec&#58; 312455   Branching&#58; 7.14
Line&#58;  Nf4d5 f7f6 Bg5xh6+ i7xh6 Bg2xj5

Ply&#58; 4-16 &#40;ended&#41;  Time 0&#58;00    Eval&#58; 115  Nodes&#58; 53982  Nodes/Sec&#58; 269910   Branching&#58; 5.96
Line&#58;  Nf4d5 f7f6 Bg5xh6+ i7xh6 Bg2xj5

Ply&#58; 5-16 &#40;start&#41;  Time 0&#58;00    Eval&#58; 105  Nodes&#58; 61300  Nodes/Sec&#58; 269910   Branching&#58; 5.96
Line&#58;  Nf4d5 f7f6 Bg5xh6+ i7xh6 Bg2xj5 Rj8f8

Ply&#58; 5-16 &#40;start&#41;  Time 0&#58;00    Eval&#58; 118  Nodes&#58; 76025  Nodes/Sec&#58; 269910   Branching&#58; 5.96
Line&#58;  Nf4h5+ g6xh5 Bg5xh6+ i7xh6 Cj4xh5+ Kg7g8 Qd2xh6 Rj8j7 Bg2xj5

Ply&#58; 5-16 &#40;ended&#41;  Time 0&#58;00    Eval&#58; 118  Nodes&#58; 262713  Nodes/Sec&#58; 301968   Branching&#58; 4.86
Line&#58;  Nf4h5+ g6xh5 Bg5xh6+ i7xh6 Cj4xh5+ Kg7g8 Qd2xh6 Rj8j7 Bg2xj5

Ply&#58; 6-18 &#40;start&#41;  Time 0&#58;00    Eval&#58; 121  Nodes&#58; 302574  Nodes/Sec&#58; 301968   Branching&#58; 4.86
Line&#58;  Nf4h5+ g6xh5 Bg5xh6+ i7xh6 Cj4xh5+ Kg7h8 Qd2xh6 Rj8j7 Bg2xj5

Ply&#58; 6-20 &#40;ended&#41;  Time 0&#58;03    Eval&#58; 121  Nodes&#58; 1030482  Nodes/Sec&#58; 328178   Branching&#58; 3.92
Line&#58;  Nf4h5+ g6xh5 Bg5xh6+ i7xh6 Cj4xh5+ Kg7h8 Qd2xh6 Rj8j7 Bg2xj5

Ply&#58; 7-22 &#40;start&#41;  Time 0&#58;03    Eval&#58; 482  Nodes&#58; 1213366  Nodes/Sec&#58; 327500   Branching&#58; 3.92
Line&#58;  Nf4h5+ g6xh5 Cj4xh5+ Kg7h8 Bg5xh6 i7xh6 Qd2xh6 Rj8j7 Ch5i5 Bd7g4

Ply&#58; 7-25 &#40;ended&#41;  Time 0&#58;05    Eval&#58; 482  Nodes&#58; 1949106  Nodes/Sec&#58; 362962   Branching&#58; 1.82
Line&#58;  Nf4h5+ g6xh5 Cj4xh5+ Kg7h8 Bg5xh6 i7xh6 Qd2xh6 Rj8j7 Ch5i5 Bd7g4

Ply&#58; 8-25 &#40;start&#41;  Time 0&#58;06    Eval&#58; 482  Nodes&#58; 2472154  Nodes/Sec&#58; 362962   Branching&#58; 1.82
Line&#58;  Nf4h5+ g6xh5 Cj4xh5+ Kg7h8 Bg5xh6 i7xh6 Qd2xh6 Rj8j7 Ch5i5 Bd7g4

Ply&#58; 8-25 &#40;ended&#41;  Time 0&#58;13    Eval&#58; 482  Nodes&#58; 5309501  Nodes/Sec&#58; 398312   Branching&#58; 2.72
Line&#58;  Nf4h5+ g6xh5 Cj4xh5+ Kg7h8 Bg5xh6 i7xh6 Qd2xh6 Rj8j7 Ch5i5 Bd7g4

Ply&#58; 9-25 &#40;start&#41;  Time 0&#58;17    Eval&#58; 482  Nodes&#58; 6968223  Nodes/Sec&#58; 400100   Branching&#58; 2.72
Line&#58;  Nf4h5+ g6xh5 Cj4xh5+ Kg7h8 Bg5xh6 i7xh6 Qd2xh6 Rj8j7 Ch5i5 Bd7g4 Ci5xg4

Ply&#58; 9-30 &#40;ended&#41;  Time 0&#58;46    Eval&#58; 482  Nodes&#58; 19873400  Nodes/Sec&#58; 425281   Branching&#58; 3.70
Line&#58;  Nf4h5+ g6xh5 Cj4xh5+ Kg7h8 Bg5xh6 i7xh6 Qd2xh6 Rj8j7 Ch5i5 Bd7g4 Ci5xg4

Depth=10, Time=1&#58;00 , Nodes=25685749, Nodes/Sec.=428095
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