v0.2.7

Performance enhancements and bug fixes.

Astellarn v0.2.5

• New evaluation terms.
• Probcut bug fix.
• History heuristic bug fix.
• Minor tweaks.

Regression testing:
1s+0.1s
PLAYER : RATING ERROR POINTS PLAYED (%)
1 Astellarn-Dev : 38.0 21.8 277.0 500 55
2 Astellarn : 0.0 ---- 223.0 500 45

1m+1s
PLAYER : RATING ERROR POINTS PLAYED (%)
1 Astellarn-Dev : 45.8 46.2 56.5 100 56
2 Astellarn : 0.0 ---- 43.5 100 44

Astellarn v0.2.4

• Pawn hash table size is now limited to prevent memory creep.
• Small performance tweaks for a minor boost in NPS.
• History heuristics are now scaled down by a factor inbetween searches to reduce "noise" and favour new quiet moves coming to the fore.
• Lazy evaluation reinstated.
• Found and fixed a bug in MVV-LVA move ordering.
• Implemented time management for "movestogo" time controls.

Regression tests (testing history heuristic noise reductions, factor of 2, 8 or without):

Time control: 1s + 0.1s
PLAYER : RATING ERROR POINTS PLAYED (%)
1 AstellarnDev-WithFact2 : 69.8 23.0 359.5 628 57
2 AstellarnDev-WithFact8 : 45.6 23.1 331.5 629 53
3 AstellarnDev-Without : 9.7 22.9 288.5 628 46
4 Astellarn-v0.2.3 : 0.0 ---- 277.5 629 44

Time control: Fixed depth search 13
PLAYER : RATING ERROR POINTS PLAYED (%)
1 AstellarnDev-WithFact2 : 35.1 40.2 106.5 200 53
2 AstellarnDev-WithFact8 : 24.6 41.9 102.0 200 51
3 AstellarnDev-Without : 0.0 ---- 91.5 200 46

Time control: 1m + 1s
PLAYER : RATING ERROR POINTS PLAYED (%)
1 AstellarnDev-WithFact8 : 127.9 58.9 63.0 100 63
2 AstellarnDev-WithFact2 : 67.6 59.5 50.5 100 50
3 AstellarnDev-Without : 0.0 ---- 36.5 100 36

Astellarn v0.2.3

• Improved pawn evaluation regarding: passed pawns, connected passed pawns.
• King safety evaluation.
• Knight evaluation bug fix.
• Pawn hash table bug fix.
• Check-threats evaluation.

1m+1s 100 game blitz regression test.
256mb hash.
PLAYER : RATING ERROR POINTS PLAYED (%)
1 Astellarn-Dev : 140.2 52.6 69.0 100 69
2 Astellarn : 0.0 ---- 31.0 100 31

Adjustable Transposition Tables

Transposition table hash memory now adjustable (and not infinite), wi…

…th UCI option support

Add cutnodes and internal iterative deepening to search

Additional evaluation terms

Stop init MoveStack and PieceStack with undefs as was leading to out of bounds errors in cmtable

Time Management Implementation.

v0.2.0

Add time management

Iterative deepening and aspiration windows

iterative deepening, aspiration windowing, syzygy rootnode eval, noch…

…eck qsearch, variable renaming

Initial UCI support release

v0.0.3

build script information