Invictus

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Invictus, (InvictusChess, Invictus Chess) an UCI compliant open source chess engine by Edsel Apostol, written in C++ and licensed under the GPL v3.0, first released in September 2018. Invictus is influenced by other open source engines in particular Stockfish, Ethereal, Defenchess, and Minic concerning Texel's Tuning Method. Tom Kerrigan of TSCP fame is given credit for sharing the Simplified ABDADA idea. Invictus r324 had its tournament debut at TCEC Season 21 in May 2021 and gained a respectable 50% score in its strong Qualification League.

=Features=

Board Representation

 * Bitboards
 * Magic Bitboards
 * PEXT Bitboards

Search

 * Iterative Deepening
 * Aspiration Windows
 * Parallel Search using Threads
 * Simplified ABDADA
 * Shared Hash Table
 * NUMA Support
 * Principal Variation Search
 * Move Ordering
 * Internal Iterative Deepening
 * Killer Heuristic
 * History Heuristic
 * MVV/LVA
 * SEE
 * Selectivity
 * Null Move Pruning
 * Late Move Reductions
 * Late Move Pruning
 * SEE Pruning
 * Futility Pruning
 * Quiescence Search

Evaluation

 * Tapered Eval
 * Material
 * Bishop Pair
 * Mobility
 * Pawn Structure
 * Open Pawns
 * Backward Pawn
 * Isolated Pawn
 * Doubled Pawn
 * Connected Pawns
 * Passed Pawn
 * King Safety
 * King Tropism
 * Pawn Shelter
 * Pawn Storm
 * Attacking King Zone
 * Tempo

Misc

 * Texel's Tuning with Stochastic Gradient Descent using Adam
 * Texel's Tuning with Local Search

=See also=
 * Twisted Logic
 * Hannibal

=Forum Posts=
 * Invictus chess engine r228 by Edsel Apostol, CCC, September 29, 2018
 * Re: New engine releases 2019 (Invictus r305) by Edsel Apostol, CCC, December 05, 2019
 * Re: New engine releases & news 2021 (Invictus r340) by Edsel Apostol, CCC, May 19, 2021
 * Re: New engine releases & news 2021 (Invictus r382) by Edsel Apostol, CCC, June 07, 2021

=External Links=

Chess Engine

 * GitHub - ed-apostol/InvictusChess: A state of the art chess playing engine
 * Invictus in CCRL 40/15

Misc

 * invictus - Wiktionary
 * Invictus (disambiguation) from Wikipedia
 * Invictus from Wikipedia
 * Oxford Book of English Verse 1250-1900/Invictus - Wikisource
 * Virgin Steele - Invictus (1998), YouTube Video

=References= Up one Level