4 Player Chess Engine

This project implements a 4 player teams chess engine.

What can you do with it?

• Play against the computer
• Analyze your games

Requirements

• Node JS
• Bazel

Command line / UCI

This project implements the chess UCI protocol.

To build, you have a couple of options:

# Option 1 (bazel):
bazel build -c opt cli

# Option 2 (Makefile):
make cli

After building, run the program:

bazel-bin/cli  # for bazel
# or just `./cli` for make

Then, analyze a position as below.

From the start position

go

From a position specified by FEN

position fen <some FEN>
go

Play against the computer

1. Initialize node js (one time):

cd ui
npm install

2. Start the server:

node-gyp install
node app.js

3. Go to http://localhost:3000

Code organization

• board.h/cc: Classes representing the board.
• player.h/cc: Classes representing the player.
• ui directory: Related to the website and UI for playing.

Run tests

# All unit tests
bazel test -c opt :all

# Performance test: you'll want to run with --test_output=all
bazel test -c opt speed_test --test_output=all

A/B tests for playing strength

Use simplechessmatch to test the strength of changes.

Example:

# A/B engine test with 250 ms per move for quick quality tests
./scm --e1 /Users/louisobryan/tmp/4pchess/cli --e2 /Users/louisobryan/4pchess/cli --fixed 250 --games 500 --threads 10 --fens FENs_4PC_balanced.txt \
    --custom1 "setoption name threads value 1" \
    --custom2 "setoption name threads value 1" \
    --pgn4 /tmp/games.pgn4 \
    --margin 3000 \
    --maxmoves 200

It is recommended to test with 5000 ms per move for confidence on the results.

Once the run completes, you can check whether the result is significant by testing whether the p-value is less than 0.05. For example,

python3 ttest.py --n_wins=243 --n_losses=199 --n_draws=25
# => Ttest_1sampResult(statistic=2.100107728239835, pvalue=0.01811446939295551)

Regression tests

bazel run -c opt regression_tests --test_output=all --runs_per_test=30