DiscoCheck 4.3 is out

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DiscoCheck 4.3 is out

Postby lucasart » Sun Jul 14, 2013 4:27 am

Official compiles
As usual, 4 compiles available, 64-bit only
  • Linux SSE 2: discocheck_4.3_sse2
  • Linux SSE 4.2: discocheck_4.3_sse4.2
  • Windows SSE 2: discocheck_4.3_sse2.exe
  • Windows SSE 4.2: discocheck_4.3_sse4.2.exe
SSE 4.2 is faster, but only works with recent CPUs. Try it first, and if it fails, use SSE 2 as a fallback.

What's new
  • bugfix: pawn hash table was not working (fixing this was a major speedup, although a non functional change)
  • simplify IID condition: now much less dependant on the predicted node type.
  • bugfix: mate scores were adjusted when being read from the TT, but not before being written. Thanks to Marco Costalba for spotting this bug.
  • only set ep-square when it can be attacked by enemy pawns.
  • apply double reductions a little bit earlier at predicted Cut nodes.
  • reduce max depth from 8 to 6 for move count pruning.
  • rook pair penalty (redundancy).
  • increase king safety penalty when the king is advanced and cannot retreat.
  • improved hanging pieces asymmetric evaluation.
  • do not sort predicted All nodes differently.
  • improved stand pat stuff in qsearch and search, using a separate asymmetric evaluation.
  • unify scoring of passed and candidate passed pawns, for better eval continuity.
  • tweak passed pawns scoring.
  • improved the formula of ELO levels.
  • skip SEE pruning and LMP at the Root node.
  • lots of code cleanup.

Based on my estimations, it should be around 2800 CCRL.

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"Talk is cheap. Show me the code." -- Linus Torvalds.
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Re: DiscoCheck 4.3 is out

Postby ChessDrone » Sun Jul 14, 2013 5:11 am

:difus_drinks Thanks
Posts: 78
Joined: Mon Jan 28, 2013 10:56 am

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