On-line engine blitz tourney December

[Henk]

not too bad. realised I was playing with only 1 thread and 512MB hash

if it plays worse then microMax then it is a badly running engine.

Micromax is zero point. Below zero it is freezing.

[Sven]

First thing I should do is get rid of database connection or dependency. For if you want to play a game but can't connect in time it's over.

Endgame evaluation needs to be rewritten/debugged too etcetera.

KPK evaluation can be kept very simple: identify a small set of standard situations where the outcome is a draw, evaluate these as 0, and let the search do the rest based on material only (no PST). Typical standard draws are (assuming the moving side is not in check, no illegal or stalemate position):

- rook pawn: defender king on same file as pawn or on neighbor file, and closer to promotion square than pawn (e.g. wPa5 and bKa6/a7/a8/b7/b8)
- non-rook pawn not on 7th (2nd) rank: defender king directly in front of pawn (e.g. wPd6, bKd7)
- non-rook pawn not on 7th (2nd) rank: defender king two squares in front of pawn and attacker to move (e.g. wPc5, bKc7, White to move)

Apart from that, some suggestions for endgame evaluation:

- Detect KK, KBK, KNK draws (can be done in search already). Optionally include king + bishops vs king where all bishops have the same square color (very rare though so it can be omitted).

- Evaluate KNNK as a draw if the side to move is the defender or the king is not on an edge square.

- Evaluate simple mating of the bare king with a separate algorithm if the stronger side has sufficient mating material (either at least a rook or at least BB or BN).

- Evaluate endgames with only a minor piece and nothing else (i.e., no pawns left) as "at most a draw".

- Scale down evaluation to e.g. 50% or 25% if the stronger side has only one pawn, no material that would be sufficient for mating without the pawn, and the defender has one minor piece (which he could sacrifice to remove the enemy pawn). Scaling factor might be adapted depending on the pawn's rank.

- In general give a bonus for the defender if he blocks an enemy's passed pawn (higher bonus for blocking with minor piece, higher bonus for blocking the passer on a lower rank).

[Sven]

KPK evaluation [...] let the search do the rest based on material only (no PST)

the "(no PST)" was a bad idea of course so remove the phrase "based on material only (no PST)". Otherwise the stronger side might fail to advance the pawn.

- non-rook pawn not on 7th (2nd) rank: defender king two squares in front of pawn and attacker to move (e.g. wPc5, bKc7, White to move)

must be: non-rook pawn neither on 7th (2nd) nor on 6th (3rd) rank: [...] (to exclude wPc6, wKd6, bKc8 where White to move wins by c6-c7)

[cdani]

Code: Select all

:Tourney Players: Round 9 of 9 
:
:     Name              Rating Score Perfrm Upset  Results 
:     ----------------- ------ ----- ------ ------ ------- 
:  1 +Texel             [2249]  12.0  [2171] [   0] =10w +12b =04w +09w =02b +03w +06b =05w +13b 
:  2 -RofChade          [1827]  12.0  [2245] [1243] +06w +08b +03w +10b =01w =04b =05w =07b +12w 
:  3 -Berta             [2038]  11.5  [2058] [ 125] +11w +09w -02b +05b =04w -01b +20w +10w +15b 
:  4 +rpiStockfish      [1942]  11.0  [2107] [ 440] +15w =05b =01b +13w =03b =02w +07w =06b =08w 
:  5 +AndScacsRB        [2163]  10.5  [2015] [  43] +18w =04w =13b -03w +19b +12w =02b =01b =07w 
:  6 +ArasanX           [2049]  10.0  [1883] [   0] -02b -10b +27w +21b +13w =08b -01w =04w +19b 
:  7 -WaspX             [1996]  10.0  [1904] [  83] +14w =13b -10w =11w +09b +19w -04b =02w =05b 
:  8 -NightmareX        [1986]  10.0  [1868] [  31] +27w -02w =18b =14w =11b =06w =10b +19w =04b
:  9 -Goldbar           [1892]  10.0  [1861] [   0] +20w -03b +21w -01b -07w +16w =18b +14b =11w 
: 10 -Schooner          [1841]  10.0  [1987] [ 690] =01b +06w +07b -02w =12b =11w =08w -03b +20w 
: 11 -Marvin            [1817]  10.0  [1889] [ 285] -03b +20w =12w =07b =08w =10b =14w +16w =09b 
: 12 -Pedone            [1944]  9.5  [1839] [   0] +19w -01w =11b +16b =10w -05b =13w +20b -02b 
: 13 -Baron             [1847]  9.5  [1929] [ 280] +16b =07w =05w -04b -06b +15w =12b +18w -01w 
: 14 +Phalanx           [1751]  9.0  [1705] [ 192] -07b =16w +17w =08b =18w -20b =11b -09w +23b 
: 15 +atomBaron         [1612]  9.0  [1656] [ 101] -04b =19b -16w =23b +21w -13b +27w +22b -03w 
: 16 -Myrddin           [1572]  9.0  [1707] [ 261] -13w =14b +15b -12w +23w -09b +17w -11b =18w
: 17 -Jumbo             [1539]  9.0  [1586] [ 298] -23w +24w -14b +22b -20w =18b -16b +31w +27w 
: 18 -Singularity       [1836]  8.5  [1682] [ 103] -05b +23b =08w -19w =14b =17w =09w -13b =16b 
: 19 -tomitankChess     [1660]  8.5  [1758] [ 176] -12b =15w +23w +18b -05w -07b +22w -08b -06w 
: 20 -Nemeton           [1581]  8.5  [1667] [ 170] -09b -11b =22w +24w +17b +14w -03b -12w -10b 
: 21 +Bliep             [1514]  8.5  [1589] [ 175] +22w +27b -09b -06w -15b +26w -31w =30b +28b 
: 22 +Floyd             [1509]  8.5  [1519] [  60] -21b +28w =20b -17w +31b +23w -19b -15w +30w 
: 23 +rpiMinkoChess     [1533]  8.0  [1508] [  45] +17b -18w -19b =15w -16b -22b +29w +24b -14w 
: 24 +Spartacus         [1475]  8.0  [1417] [ 120] +28w -17b +25w -20b =27w -31b +35b -23w +36b
: 25 -KingSlayer        [1391]  8.0  [1371] [  34] =31w +29b -24b -28w +36b -30b +38w +40b +35w 
: 26 +Embla             [1313]  8.0  [1448] [ 236] +34w -32w +38b +29b +30w -21b -28b +39w +31b 
: 27 +Viper             [1689]  7.5  [1410] [   0] -08b -21w -06b -31w =24b +28w -15b +32w -17b 
: 28 +rpiFruit          [1488]  7.5  [1402] [   0] -24b -22b =30w +25b +32w -27b +26w =29b -21w 
: 29 +Joker             [1425]  7.5  [1320] [  31] =30w -25w =31b -26w +33b +34w -23b =28w +39b 
: 30 -Isa               [1414]  7.5  [1367] [  92] =29b -31w =28b +34w -26b +25w +37b =21w -22b 
: 31 -CTdccc            [1336]  7.5  [1518] [ 819] =25b +30b =29w +27b -22w +24w +21b -17b -26w 
: 32 -Weini             [1292]  7.5  [1385] [  21] +33w +26b -34w +35b -28b +37w +36b -27b +40w
: 33 +microMax          [1213]  7.0  [1238] [  46] -32b =34b +35w +37b -29w +40w +39b -36w +38w 
: 34 -Eichhoernchen     [1306]  6.5  [1197] [   0] -26b =33w +32b -30b +39w -29b +40w +38b -37w 
: 35 +rpiPhalanx        [1171]  5.5  [1168] [   0] =38w +36w -33b -32w +40b +39b -24w +37b -25b 
: 36 +rpiBikjump        [1033]  5.5  [1228] [ 318] +37w -35b +40w +39b -25w +38b -32w +33b -24w 
: 37 -Skipper           [1027]  4.0  [1079] [ 423] -36b +40w =39b -33w +38b -32b -30w -35w +34b 
: 38 -Skiull            [1171]  3.5  [ 974] [   0] =35b +39w -26w +40b -37w -36w -25b -34w -33b 
: 39 +LessThanOne       [ 891]  1.5  [ 920] [ 204] +40b -38b =37w -36w -34b -35w -33w -26b -29w 
: 40 +NEG               [1027]  0.0  [ 766] [   0] -39w -37b -36b -38w -35w -33b -34b -25w -32b
:
:     Average Rating    1584.0 
:

I'm curious about this "AndScacsRB". Someone knows what is? Thanks

[Daniel Anulliero]

I Guess its an AndScacs ran by Ray Banks, thats Why It is
AndScacsRB
Merry Christmas Daniel !

[cdani]

I Guess its an AndScacs ran by Ray Banks, thats Why It is
AndScacsRB
Merry Christmas Daniel !

Thanks! Merry Christmas!!

[hgm]

Ray Banks is a much appreciated participant of these tourneys, who often runs interesting engines. But to leave open the possibility that the author himself would ever want to participate with this engine under its own name, I give the ICS accounts that Ray uses to run them not just the name of the engine, but always append an RB suffix.

[Modern Times]

Yes it is me. In the past I've run Trace, Crafty, Cheng, Nirvanachess, Gaviota, Stockfish and maybe some others I've forgotten. Graham suggested this time that I run AndScacs. There have been occasions when the author himself has participated, in which case I choose a different engine. There are so many particpants these days it can be difficult to find an engine that isn't already there ! But I've been absent for a while due to other commitments at the time.

[cdani]

Yes it is me. In the past I've run Trace, Crafty, Cheng, Nirvanachess, Gaviota, Stockfish and maybe some others I've forgotten. Graham suggested this time that I run AndScacs. There have been occasions when the author himself has participated, in which case I choose a different engine. There are so many particpants these days it can be difficult to find an engine that isn't already there ! But I've been absent for a while due to other commitments at the time.

Nice! As you wish It's difficult for me to be there for the tournament.
Best regards.