Radiance Engine

C++ chess engine

Move Generation and Ordering

• Precomputed Bitboard Move Generation
• Transposition Table Move Ordering
• Principal Variation Move Ordering
• MVV-LVA

Search

• Principal Variation Search
• Alpha-Beta Pruning
• Aspiration Window
• Late Move Reduction
• Quiescence Search
• Threefold Repetition
• Time Management

Evaluation

• Tuned Piece-square Tables
• AlphaZero Average Piece Values
• Bitboard Evaluation
• Transposition Table Evaluation
• Endgame Heuristics
• Pawn Structures Heuristics

Versions tournament

Time control: 120+1

CCRL blitz benchmark.

Rank	Name	CCRL	Elo	+/-	Games	Score	Draw
1	radiance_3.4	1302	345	6	22528	87.9%	6.4%
2	radiance_3.2		295	6	22528	84.5%	7.0%
3	radiance_3.3		294	6	22528	84.4%	7.4%
4	radiance_3.1.1	1118	188	5	22528	74.7%	7.7%
5	radiance_2.4		54	4	22528	57.8%	8.8%
6	radiance_3.0.1		39	4	22528	55.6%	7.6%
7	radiance_2.3	866	38	4	22528	55.5%	8.7%
8	radiance_2.2		-136	5	22528	31.3%	4.1%
9	radiance_2.1		-147	5	22528	30.1%	3.2%
10	radiance_2.0		-170	5	22528	27.3%	2.6%
11	radiance_1.5		-375	7	22528	10.4%	0.2%
12	radiance_1.4		-957	36	22528	0.4%	0.0%

Getting started

Compilation

export CXX=g++-12
export CC=gcc-12
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make
./radiance
go
stop

UCI options

Name	Type	Default value	Valid values	Description
Hash	spin	256	[1, 131072]	Memory allocated to the transposition table (in MB).
Threads	spin	1	[1, 1]	Number of threads used to search.
Evaluation	combo	"PSQTunedBB"	[ "PSQTunedBB", "PSQTuned", "PSQ", "Shannon", "ShannonHeuristics"]	Type of evaluation function.
Search	combo	"abNegamax"	["abNegamax", "Minimax", "Random"]	Type of search function.

Commands

• uci
• isready
• setoption name <id> [value <x>]
• position [fen <string> | startpos | kiwi | lasker] [moves <string>...]
• go [movetime <int> | [wtime <int>] [btime <int>] [winc <int>] [binc <int>] | depth <int> | infinite | perft <int>]
• stop
• quit
• ucinewgame
• d

I'm radiant!