Hakkapeliitta

an UCI compatible open source chess engine by Mikko Aarnos, written in C++11/14 and licensed under the GNU General Public License, Version 3. Hakkapeliitta is a state of the art bitboard engine, and performs Magic bitboards to determine sliding piece attacks. Despite using conditional compiled x86-64 processer instructions for bitscan, Hakkapeliitta uses Kim Walisch's forward and reverse bitscans. If the processor does not support hardware popcount, Hakkapeliitta falls back to SWAR-popcount. The search uses [|function templates] to distinguish between PV-nodes and none PV-nodes at compile time. Similar, hardware popcount support is boolean template parameter of evaluation routines. || toc =Etymology= The term is probably based on the [|Finnish] [|battle cry] "Hakkaa päälle", commonly translated as "Cut them down!". The Finnish [|cavalryman] in the service of [|King] [|Gustavus Adolphus] of [|Sweden] during the [|Thirty Years' War] (1618 to 1648) were called Hackapelit, Hackapelite, Hackapell, Haccapelit, or Haccapelite in the [|Holy Roman Empire], in the [|19th-century] modified to Finnish **Hakkapeliitta**.
 * Home * Engines * Hakkapeliitta**
 * [[image:Hakkapeliitta-1940.jpg link="http://commons.wikimedia.org/wiki/File:Hakkapeliitta-1940.jpg"]] ||~ || **Hakkapeliitta**,
 * Hakkapeliitta ||~ ||^ ||

=Features=

Search

 * Iterative Deepening
 * Aspiration Windows
 * Principal Variation Search
 * Transposition Table
 * Zobrist Hashing
 * Null Move Pruning
 * Late Move Reductions
 * Internal Iterative Deepening
 * Futility Pruning
 * Move Count Based Pruning
 * Reverse Futility Pruning
 * Razoring
 * Killer Heuristic
 * Relative History Heuristic
 * Static Exchange Evaluation

Evaluation
> Backward Pawn > Doubled Pawn > Isolated Pawn > Passed Pawn > Pawn Shelter
 * Material
 * Tapered Eval
 * Piece-Square Tables
 * Mobility
 * Pawn Hash Table
 * Pawn Structure
 * King Safety

Misc

 * Magic Bitboards
 * Perft
 * Pondering (since 3.0)
 * Syzygy Bases

=Acknowledgements= Thanks from the author to following people or organizations
 * Chess Programming Wiki (Thanks as well)
 * Talkchess
 * Tord Romstad of Glaurung
 * Ronald de Man
 * Tord Romstad, Marco Costalba, and Joona Kiiski of Stockfish
 * Robert Hyatt of Crafty
 * Peter Österlund of Texel
 * Authors of Ivanhoe
 * Ed Schröder of Rebel and Pro Deo
 * Stef Luijten of Winglet
 * Steve Maughan of Maverick
 * Tom Kerrigan of TSCP

=See also=
 * Military

=Forum Posts=
 * [|Hakkapeliitta dev 63.7 by Mikko Aarnos] by Jose Mº Velasco, CCC, February 25, 2014
 * [|Hakkapeliitta 1.0 release] by Mikko Aarnos, CCC, June 22, 2014
 * [|Hakkapeliitta 2.0 release] by Mikko Aarnos, CCC, December 25, 2014
 * [|Hakkapeliitta 3.0 release] by Mikko Aarnos, CCC, June 27, 2015
 * [|Hakkapeliitta the "STRONGEST" in tactic, new Nr1] by Frank Quisinsky, CCC, July 19, 2015

=External Links=

Chess Engine

 * [|mAarnos/Hakkapeliitta · GitHub]
 * [|Hakkapeliitta] in CCRL 40/4

Misc
> media type="youtube" key="_rcgloApnUs" width="560"
 * [|Hakkapeliitta - Wiktionary]
 * [|Hakkapeliitta from Wikipedia]
 * [|Hakkapeliittain Marssi from Wikipedia]
 * [|Hakkapeliitta (lehti) Wikipedia] (Finnish, Paramilitary Journal 1926 - 1944)
 * [|Mossy Rocks] - Cut Em Down, [|YouTube] Video

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