- Great bustard, Image by Andrej Chudý, March 30, 2008, Wikimedia Commons↩︎
Drofa,
an UCI compliant open source chess engine by Alexander Litov, written in C++ 11, and first released in August 2020 under the MIT License 1. Drofa started as fork of Shallow Blue and improved considerably in subsequent versions, also incorporating knowledge from several open source engines such as Vice, Weiss, Ethereal and Stockfish, due to AdaGrad tuning as proposed by Andrew Grant, and using Koivisto's OpenBench instance 2.
Contents
Features
Board Representation
Search
- Lazy SMP (3.0.0)
- Iterative Deepening
- Aspiration Windows (3.0.0) 3
- Principal Variation Search
- Transposition Table
- Move Ordering
- Selectivity
- Check Extensions
- Passed Pawn Extensions (2.0.0)
- Null Move Pruning (1.0)
- Late Move Reductions (2.0.0)
- Late Move Pruning (2.0.0)
- Razoring (2.0.0)
- Extended Futility Pruning (2.0.0)
- Reverse Futility Pruning (2.0.0)
- Quiescence Search
- Delta Pruning
Evaluation
- Tapered Eval
- Material
- Piece-Square Tables
- Mobility
- Outposts
- Pawn Hash Table (1.0)
- Pawn Structure
- King Safety
- King Pawn Tropism (2.2.0)
- Tempo (2.2.0)
- Automated Tuning by Logistic Regression, AdaGrad (3.0.0)
See also
Forum Posts
- Drofa 1.0 by Alexander Litov, CCC, August 31, 2020
- Re: Is cloning a hobby? by Alexander Litov, CCC, September 19, 2020
- Drofa 2.0.0 by Alexander Litov, CCC, November 09, 2020
- Re: Are Aspiration Windows Worthless? by Alexander Litov, CCC, December 23, 2020 » Aspiration Windows
- Drofa 2.2.0 by Alexander Litov, CCC, February 01, 2021
- Re: New engine releases & news (Drofa 3.0.0) by Alexander Litov, CCC, April 17, 2021
External Links
Chess Engine
Misc
References
Drofa 1.0 by Alexander Litov, CCC, August 31, 2020↩︎
Re: Are Aspiration Windows Worthless? by Alexander Litov, CCC, December 23, 2020↩︎