Defenchess – AI Chess Engine
A high-performance C++ engine for advanced chess analysis and play. Previously ranked in the top-10 worldwide with a 3400+ ELO performance.
Defenchess is a UCI compliant open source chess engine by Can Cetin and Dogac Eldenk, written in C++ and licensed under GPL v3.0. Defenchess evolved from the authors’ former engine SCTR, and had its tournament debut at TCEC Season 11 in 2018, where it won the Fourth Division.
Features
Board Representation
- 8x8 Board
- Bitboard Board-Definition
- Plain Magic Bitboards
Search
- Lazy SMP - Parallel search implementation
- Iterative Deepening
- Alpha-Beta with Principal Variation Search
- Transposition Table
Selectivity
- Null Move Pruning
- ProbCut
- SEE Pruning
- Late Move Reductions
- Futility Pruning
- Razoring
- Check Extensions (if SEE >= 0)
- Restricted Singular Extensions
- Quiescence Search
Move Ordering
- PV-Move
- Countermove Heuristic
- History Heuristic
- Killer Heuristic
- Captures by MVV/LVA
- Static Exchange Evaluation
Evaluation
- Tapered Eval
- Material
- Mobility
- Bad Bishop
- Rooks on (Semi) Open Files
- Pawn Structure
- Pawn Hash Table
- Isolated Pawns
- Doubled Pawns
- Backward Pawns
- Passed Pawns
- King Safety
- Pawn Shelter
- Pawn Storms
- Enemy Attacks
- Tempo Bonus