DiscoCheck

DiscoCheck New name for "DoubleCheck" (UCI)
Author: Lucas Braesch, France.
http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

Last edited by Steve.R on Mon May 14, 2012 5:26 pm; edited 4 times in total (Reason for editing : DiscoCheck New name for "DoubleCheck!!)

DoubleCheck 2.0 for Android is available
Download
http://www.aartbik.com/MISC/eng.html

Doublecheck 2.0 JA (Windows/Linux/Android 64/32 p.g.o)
Download
http://jim-ablett.co.de/

New 64 bit linux compile to test using link-time optimizations
http://dl.dropbox.com/u/5047625/doublecheck-20-64-lin-new-ja.zip

DoubleCheck 2.4 released

change log:

- search: rewrote the PVS + reduction bit a little. Thanks to Marco Costalba for his advice on this.
- MAX_GAME_PLY now equals 0x400, so games can safely last 0x400-0x80 half-moves before the game stack.
writes out of its allocated memory and crashes everything.
- qsearch: do not write in the TT when the move loop was empty.
- eval: mobility rewritten, should make a bit more sense now.
- search: introduced double reductions for late quiet moves.
- search: do not reduce castling moves.
- search: eval pruning rather than reduce.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 2.4 JA
Windows/Linux/Android 64/32 p.g.o

Download:
http://dl.dropbox.com/u/5047625/doublecheck-24-ja.zip
Mirror:
http://cl.ly/DNU8/doublecheck-24-ja.zip

DoubleCheck 2.5 released
(Windows-x64, Linux-x64 and sources included!)

change log:

Essentially it fixes a time bug, and introduces a king attack evaluation component.
About +70 elo in self-play.

- eval: added a very simplistic king attack bonus mechanism.
- bugfix: doubled the node polling frequency to avoid time losses.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

Doublecheck 2.5 JA
http://dl.dropbox.com/u/5047625/doublecheck-25-ja.zip
http://cl.ly/DWqp/doublecheck-25-ja.zip

DoubleCheck 2.51 released

change log:
- eval: added candidate passed pawns.
- bugfix: report correct version number.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 2.52 released

change log:
- eval: removed candidate passed pawns.
- eval: reduced penalty when a passed pawn is not part of a pawn chain.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 2.5.3
-----------------
- move_ok: rewritten efficiently (first step to prepare the lazy move ordering).
- rook and bishop promotions can be disabled (in search, not perft) with SubPromotions in movegen.c
- gen_msl: precalculate SEE only for captures.

http://www.wbec-ridderkerk.nl/html/downloada/doublecheck/DoubleCheck_253.zip

DoubleCheck 2.54 released

change log:
- bugfix: free passer bonus was attributed when pieces were in the way, i/o the opposite.
- bugfix: relative king distance was too preponderant in the passed pawn scoring.
- bugfix: KRRBKRR was incorrectly recognized as a draw.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 2.5.4 JA
Windows/Linux/Android 64/32

Download:
http://dl.dropbox.com/u/5047625/doublecheck-254-ja.zip
Mirror:
http://cl.ly/E3vm/doublecheck-254-ja.zip

DoubleCheck 2.5.4 (Mac PPC build by Matthew)
http://www.thelumpit.net/DoubleCheck_254_Mac.zip

DoubleCheck 2.6

- eval_loose: penalise loose pieces a little.
- introduced an array B->st->attacks[color][piece] to simplify and speedup additional eval code.
- use unsigned i/o int wherever relevant.
- faster interfacing code when Verbose = false.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 2.6 JA
Windows/Linux/Android 64/32

Download:
http://dl.dropbox.com/u/5047625/doublecheck-26-ja.zip
Mirror:
http://cl.ly/EWgL/doublecheck-26-ja.zip

DoubleCheck 2.7 (Windows-x64, Linux-x64 and sources included!)
http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

- added rook on open file bonus.
- removed stdin unbuffering.
- removed the global variable SubPromotion. handle this more tidily via function parameter.
- changed piece values.
- mvv/lva sort in qsearch captures.
- removed RNB promotions in qsearch.
- remove POSIX compile flag (auto detect).

DoubleCheck 2.7 JA
Windows/Linux/Android 64/32

http://dl.dropbox.com/u/5047625/doublecheck-27-ja.zip
http://cl.ly/EvLG/doublecheck-27-ja.zip

DoubleCheck 3.0

- eval command now returns a full breakdown of eval components.
- eval mostly rewritten.
- aspiration windows.
- code cleanup.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 3.0 JA (updated 21-03-12)

Windows/Linux/Android 64/32

http://dl.dropbox.com/u/5047625/doublecheck-30-ja.zip
http://cl.ly/FCmb/doublecheck-30-ja.zip

DoubleCheck 3.1

- futility pruning in quiescent search improved.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 3.1 JA

Windows/Linux/Android 64/32

http://dl.dropbox.com/u/5047625/doublecheck-31-ja.zip
http://cl.ly/FSwK/doublecheck-31-ja.zip

DoubleCheck 3.2

- eval: increase rook on (semi)open file bonus, when on the enemy's king file.
- eval: added a tempo bonus.
- search: margin for eval pruning now increases faster with depth.
- search: fixed my lame razoring code. thanks to Martin Sedlak and Marco Costalba for suggesting this.
- qsearch: divided by 2 the futility margin.
- qsearch: SEE pruning only at non PV nodes.
- qsearch: fixed an error in evasion pruning.
- bench: increased depth of test positions.

http://wbec-ridderkerk.nl/html/details1/DoubleCheck.html

DoubleCheck 3.2 JA

Windows/Linux/Android 64/32

http://dl.dropbox.com/u/5047625/doublecheck-32-ja.zip
http://cl.ly/FjTc/doublecheck-32-ja.zip