Freyr

a WinBoard compliant open source chess engine written by Andrei Fortuna in C++, intended as a test ground for various chess algorithms, first released in February 2000. Freyr is a bitboard engine and uses rotated bitboards to determine sliding piece attacks. The search is PVS with null move pruning inside an aspiration window iterative deepening framework with transposition table, using several move ordering heuristics, such as killer, history and countermove, as well as SEE to order captures. Lazy evaluation considers incremental updated material- and piece-square table scores and cached pawn structure stuff. Evaluation further includes king safety and passed pawns as most dominant terms. || toc =See also=
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 * [[image:Freyr_by_Johannes_Gehrts.jpg link="http://en.wikipedia.org/wiki/File:Freyr_by_Johannes_Gehrts.jpg"]] ||~ || **Freyr**,
 * [|Freyr] and [|Gullinbursti] ||~ ||^ ||
 * Mythology
 * Thor's Hammer

=Forum Posts=
 * [|New Winboard Program] by Đorđe Vidanović, Winboard Forum, February 15, 2000
 * [|A New Release of my Amateur Chess Engine Freyr] by Andrei Fortuna, CCC, February 22, 2000
 * [|Freyr 0.960 released] by Andrei Fortuna, Winboard Forum, February 29, 2000
 * [|A Question on simple Alpha-Beta versus PVS/Negascout] by Andrei Fortuna, CCC, March 21, 2000 » Alpha-Beta, Principal Variation Search, NegaScout
 * [|Freyr 0.987 Released] by Andrei Fortuna, Winboard Forum, April 30, 2000
 * [|Freyr 1.015 Released] by Andrei Fortuna, Winboard Forum, May 29, 2000
 * [|Freyr 1.024 sees the daylight] by Andrei Fortuna, Winboard Forum, June 02, 2000
 * [|Freyr 1.067] by Andrei Fortuna, Winboard Forum, September 15, 2000

=External Links=

Chess Engine

 * [|Planet Source Code™ | Freyr - A Chess Playing Program] by Andrei Fortuna
 * [|Freyr 1.068 64-bit] in CCRL 40/4

Misc
> [|Yngvi-Freyr from Wikipedia]
 * [|Freyr from Wikipedia]
 * [|Frey (disambiguation) from Wikipedia]
 * [|Freyja from Wikipedia]

=References= =What links here?= include page="Freyr" component="backlinks" limit="40"
 * Up one level**