Shikamaru will be able to:
- Play standard chess - think and play against you
- Play Chess960 - Play from any random chess state
- Force move - Play the best move that has been processed within a span of time
- Timing - Limit the complete gameplay by the engine to a specific amount of time
Shikamaru will be much faster and intelligent than the Shakti-Chess-Engine.
Shikamaru implements:
- Bitboards
- Interative Deepening
- Multi-Threading
- Alpha-Beta Pruning
- Transposition Tables
- Aspiration Windows
- Principal Variation Search
- Advanced Theoretical Evaluation
There will be a few more things along with the above.
Shikamaru is written in C++ completely and is inspired by Orion Chess Engine.
Some implementation details: - Characters 'r' & 'R' represent a Rook - Characters 'n; & 'N' represent a Knight - Characters 'b' & 'B' represent a Bishop - Characters 'q' & 'Q' represent a Queen - Characters 'k' & 'K' represent a King - Characters 'p' & 'P' represent a Pawn - The lower-case characters represent a black piece while the upper-case characters represent a white piece
The bits are counted from the top-left corner to the bottom-right corner in that order.
The moves.hpp file consists of all the move generation code of the chess-engine. Tricks used here: - Some basic bit manipulation for pawn movements - Hyperbola Quintessence which applies to the o^(o-2r) trick for bishop, rook and queen movements - Added moves for king and knight using sliding constant mask values - Added king danger detection from opponent's piece - Added basic castling technique (for each side, queen and king)
The chess engine is checked for optimizations throught Perft Debugging, and hopefully doesn't contain any problems. :P
UCI protocol is integrated to connect the chess to any GUI. Checked for Arena.
// GUI: tell the engine to use the UCI protocol uci
// ENGINE: identify
id name Chess Engine
id author John Smith
// ENGINE: send the options that can be changed // in this case the hash size can have a value from 1 to 128 MB option name Hash type spin default 1 min 1 max 128
// ENGINE: sent all parameters and is ready uciok
// GUI: set hash to 32 MB setoption name Hash value 32
// GUI: waiting for the engine to finish initializing isready
// ENGINE: finished setting up the internal values and is ready to start readyok
// GUI: let the engine know if starting a new game ucinewgame
// GUI: tell the engine the position to search position startpos moves e2e4
// GUI: tell the engine to start searching // in this case give it the timing information in milliseconds go wtime 122000 btime 120000 winc 2000 binc 2000
// ENGINE: send search information continuously during search // this includes depth, search value, time, nodes, speed, and pv line info depth 1 score cp -1 time 10 nodes 26 nps 633 pv e7e6 info depth 2 score cp -38 time 22 nodes 132 nps 2659 pv e7e6 e2e4 info depth 3 score cp -6 time 31 nodes 533 nps 10690 pv d7d5 e2e3 e7e6 info depth 4 score cp -30 time 55 nodes 1292 nps 25606 pv d7d5 e2e3 e7e6 g1f3
// ENGINE: return the best move found bestmove d7d5