Difference between revisions of "Floyd"

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'''Floyd''',<br/>
 
'''Floyd''',<br/>
an [[UCI]] compliant [[Open Source Engines|open source chess engine]] for study purposes and prototyping of new ideas by [[Marcel van Kervinck]], written in [[C]], and first released in October 2015 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=57913 Floyd 0.5 released] by [[Marcel van Kervinck]], [[CCC]], October 11, 2015</ref> with a permissive license <ref>[https://github.com/kervinck/floyd/blob/master/LICENSE floyd/LICENSE at master · kervinck/floyd · GitHub]</ref> . Floyd can be build to run under [[Windows]], [[Linux]] and [[Mac OS]]. Floyd had its over the board tournament debut at the [[IGT 2016]] with a 50% score.  
+
an [[UCI]] compliant [[:Category:Open Source|open source chess engine]] for study purposes and prototyping of new ideas by [[Marcel van Kervinck]], written in [[C]], and first released in October 2015 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=57913 Floyd 0.5 released] by [[Marcel van Kervinck]], [[CCC]], October 11, 2015</ref> with a permissive license <ref>[https://github.com/kervinck/floyd/blob/master/LICENSE floyd/LICENSE at master · kervinck/floyd · GitHub]</ref> . Floyd can be build to run under [[Windows]], [[Linux]] and [[Mac OS]]. Floyd had its over the board tournament debut at the [[IGT 2016]] with a 50% score.  
  
 
=Description=  
 
=Description=  

Revision as of 13:41, 26 June 2018

Home * Engines * Floyd

Hurricane Floyd [1]

Floyd,
an UCI compliant open source chess engine for study purposes and prototyping of new ideas by Marcel van Kervinck, written in C, and first released in October 2015 [2] with a permissive license [3] . Floyd can be build to run under Windows, Linux and Mac OS. Floyd had its over the board tournament debut at the IGT 2016 with a 50% score.

Description

Board Representation

Floyd uses an 8x8 Board, agnostic to square indexing, in the sense that it can be adapted to any of the eight possible board geometries with just a local change [4] . It uses an attack table, for each side an array of 64 bytes, with following one- or two-bit attack counters per square ...

+-----+-----+-----+-----+-----+-----+-----+-----+
|   Pawns   |   Minors  |   Rooks   |Queen|King |
+-----+-----+-----+-----+-----+-----+-----+-----+
     7..6        5..4        3..2      1     0

... as used in move generation, SEE and evaluation.

Search

The search is a classical PVS iterative deepening approach with Zobrist key transposition table, quiescence search, null move pruning and mate distance pruning. Move ordering considers SEE and a simple killer heuristic.

Evaluation

Floyd's evaluation employs a vector of feature and weight pairs to calculate a score as weighted sum. In conjunction with a draw model [5] using sigmoid functions, the score is mapped to winning probabilities, suited for logistic regression tuning.

def evaluate(board, wiloVector, drawVector):
        wiloScore = ...snip... // a weighted sum of board features
        drawScore = ...snip... // another weighted sum of board features

        return sigmoid(drawScore) * 0.5
             + sigmoid(wiloScore)
             - sigmoid(wiloScore) * sigmoid(drawScore)

Misc

Floyd provides a Python API for search and evaluation functions [6] , i.e. for automated tuning [7] . It generates a compact KPK tablebase to deal with perfect knowledge, also available as stand alone project [8] [9] .

See also

Forum Posts

External Links

Chess Engine

Misc

References

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