UCI Chess engine written in C++11
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.
scripts Remove perft_viewer.py Jan 9, 2018
test Add eval test for pawn shields not on rank 2/7 Jan 11, 2018
.gitignore Add books and .vscode to .gitignore Jan 9, 2018
.travis.yml Make clang builds work on Travis Dec 26, 2017
Doxyfile Shallow Blue v1.1.0 Jan 11, 2018
LICENSE Update copyright year in license Jan 5, 2018
build_windows.sh Add Windows build script Sep 21, 2017


Shallow Blue

(not Deep Blue)

A UCI chess engine written in C++11



To build on *nix:


You can build with debugging symbols and no optimizations using:

make debug

If you have Mingw-w64 installed, you can cross compile for Windows on Linux with:



Catch unit tests are located in the test directory.

To build and run the unit tests, use:

make test

To build and run the unit tests, skipping perft tests (these take a while to run), use:

make test-noperft


Shallow Blue's code is extensively documented with Doxygen.

To generate HTML documentation use:


Opening Books

Shallow Blue supports PolyGlot formatted (.bin) opening books. To use an opening book, the OwnBook and BookPath UCI options must be set to true and the path to the opening book file respectively.

These options can be set from your chess GUI or the UCI interface as follows:

setoption name OwnBook value true
setoption name BookPath value /path/to/book.bin

Implemented non UCI Commands

These commands can be useful for debugging.

  • perft <depth>
    • Prints the perft value for each move on the current board to the specified depth
  • printboard
    • Pretty prints the current state of the game board
  • printmoves
    • Prints all legal moves for the currently active player

Future Improvements

  • Magic bitboard move generation
  • Staged move generation
  • Game phase based evaluation
  • More sophisticated king safety evaluation


MIT © Rhys Rustad-Elliott