Aart's Blog

Jim Ablett kindly ported Gary Linscott's engine GarboChess 3 to various platforms, including Android. I also made a dynamically linked binary available at the UCI engines for Android website . As can be seen in the screenshot below, the UCI engines does not provide many options, but it plays strong. Below the results of several quick matches on a Nexus S using random book opening play, one second-per-move, 32MB hash, and 8MB tablebases cache with the 3- and 4-piece Nalimov, Gaviota, Scorpio, Robbobases endgames on SD card. GarboChess3  - Stockfish 2.1         +0/-10/=0    0.00%  - Komodo32 2.03 AB      +0/-10/=0    0.00%  - IvanHoe-Beta v999947c +0/-10/=0    0.00%  - Pepito v1.59          +3/-4/=3    45.00%  - GarboChess3 JA        +2/-3/=5    45.00%  - GNU Chess 5.07.170.7b +7/-3/=0    70.00%  - Gaviota v0.83.0.3     +7/-3/=0    70.00%  - Rotor 0.6a            +6/-2/=2    70.00%  - RedQueen 0.9.8        +9/-1/=0    90.00%  - BikJump v2.1P         +9/-0/=1    95.00%

To test recently released versions of Android engines, I conducted a new tournament between the top UCI engines on a Nexus One using a random book opening play, one second-per-move, 32MB hash, and 8MB tablebases cache with the 3- and 4-piece Robbobases endgames on SD card. Congrats again to the Stockfish team!                        1         2         3         4         5 1 Stockfish 2.1            *     54.0-46.0 60.5-39.5 64.5-35.5 65.5-34.5 244.5/400 2 Komodo32 2.03 AB     46.0-54.0     *     46.5-53.5 52.5-47.5 66.0-34.0 211.0/400 3 Critter 1.2 32-bit   39.5-60.5 53.5-46.5     *     51.5-48.5 58.0-42.0 202.5/400 4 RobboLito 0.085e4l   35.5-64.5 47.5-52.5 48.5-51.5     *     62.0-38.0 193.5/400 5 IvanHoe-Beta 999947c 34.5-65.5 34.0-66.0 42.0-58.0 38.0-62.0     *     148.5/400

Richard Vida released Critter 1.2 for various platforms, including ARM-based Android devices. Below you can see some screenshots of this UCI engine running in Chess for Android . To get a rough idea of the strength of this new engine, I conducted a few quick matches with other engines on a Nexus One using a random book opening play, one second-per-move, 32MB hash, and 8MB tablebases cache with the 3- and 4-piece Nalimov, Gaviota, Scorpio, Robbobases endgames on SD card. More games upcoming. Critter 1.2  - RobboLito 0.085e4l     3.5 - 6.5  +2/-5/=3   35.00%  - Komodo32 2.03 AB       5.0 - 5.0  +4/-4/=2   50.00%  - Stockfish 2.1          6.0 - 4.0  +4/-2/=4   60.00%  - GNU Chess 5.07.170.7b  7.0 - 3.0  +7/-3/=0   70.00%  - Gaviota v0.83          8.0 - 2.0  +7/-1/=2   80.00%  - Rotor 0.6a             9.5 - 0.5  +9/-0/=1   95.00%  - Toga II 1.4.1SE        9.5 - 0.5  +9/-0/=1   95.00%  - RedQueen 0.9.8        10.0 - 0.0 +10/-0/=0  100.00%  - BikJump v2.1P         10.0 - 0.0 +10/-0/

The new Komodo has been heavily tested by many chess fans, and Larry and Don had to make a few bug fixes. You can find an Android binary of the latest version 2.03 at the usual place . Quick tournament on a Nexus S: 1   Komodo32 2.03 AB  +34/-23/=43 55.50%   55.5/100 2   Komodo32 2.01 AB  +23/-34/=43 44.50%   44.5/100

Another tournament between the top engines on a Nexus One, 32MB hash, one-second per move.                      1           2           3                                    1 Stockfish 2.0      ***         48.5 - 51.5 59.0 - 41.0 107.5/200 2 RobboLito 0.085e4l 51.5 - 48.5 **          50.0 - 50.0 101.5/200 3 Komodo32 2.01 AB   41.0 - 59.0 50.0 - 50.0 **           91.0/200

Don Dailey and Larry Kaufman released version 2 of their chess engine Komodo. You can find an ARM-based Android binary on UCI engines for Android . The new release seems stronger than the already impressive previous version. A quick one second-per-move, 32MB hash tournament on a Nexus S against Komodo1.3 resulted in 73 vs. 27 in favor of Komodo2. 1   Komodo32 2AB     +58/-12/=30 73.00%   73.0/100 2   Komodo32 1.3 JA  +12/-58/=30 27.00%   27.0/100 The new Komodo scored 48.5% against Stockfish 2.1 under the same settings. 1   Stockfish 2.1  +38/-35/=27 51.50%   51.5/100 2   Komodo32 2AB   +35/-38/=27 48.50%   48.5/100

After this previous tournament , I conducted a tournament between various versions of the top engines under the same settings with more games. The results are shown below. Congrats to the stockfish team for winning this tournament!                            1 Stockfish 2.0           323.5/500 2 Stockfish 2.1           316.5/500 3 RobboLito 0.085e4l      250.5/500 4 RobboLito 0.085g3l      240.0/500 5 IvanHoe-Beta v999947c   196.5/500 6 Komodo32 1.3 JA         173.0/500

I conducted a full tournament between 17 currently available UCI engines for Android as well as the simple built-in Java engine. The tournament consisted of pair-wise matches between all engines for 10 games with random book opening play, one second-per-move, 32MB hash, and 8MB tablebases cache with the 3- and 4-piece Nalimov, Gaviota, Scorpio, Robbobases endgames on SD card. The 1530 games lasted about two days running full time on a Nexus One phone (without a single crash!). The results are shown below. 1  Stockfish 2.0                   157.5/170 2  RobboLito 0.085g3l              152.5/170 3  IvanHoe-Beta version 999947c    145.0/170 4  Komodo32 1.3 JA                 137.0/170 5  Toga II 1.4.1SE                 130.5/170 6  Pepito v1.59                    104.0/170 7  Daydreamer 1.75 JA              100.5/170 8  Rotor 0.6a                       98.0/170 9  gaviota v0.80.0.107              87.5/170 4647.75 10 GNU Chess 5.07.170.7b            87.5/170 4455.25 11 RedQuee

Another test tournament between different Android Stockfish versions and compilations (from Jim Ablett and myself ).            1          2          3          4          5          6           1 2.0      ********** 01½11½01½0 0½1½0100½½ 010½½½½½½1 ½1011½½½½1 ½11001½½11 27.5/50 2 2.1 JA   10½00½10½1 ********** 1½½1½1½100 ½½11½00111 1½011½½010 1½00001½1½ 27.0/50 3 2.1.1 JA 1½0½1011½½ 0½½0½0½011 ********** ½½½1½10½½½ 0½0010½½½½ ½½1½101½½1 25.5/50 4 1.9      101½½½½½½0 ½½00½11000 ½½½0½01½½½ ********** 100½1½0½1½ 1½10½0111½ 24.5/50 5 2.1      ½0100½½½½0 0½100½½101 1½1101½½½½ 011½0½1½0½ ********** ½½010½0101 24.0/50 6 1.8      ½00110½½00 0½11110½0½ ½½0½010½½0 0½01½1000½ ½½101½1010 ********** 21.5/50

I am generalizing the engine match feature in Chess for Android  into an engine tournament feature, where several engines can be invited at once, after which the GUI plays matches between all engine pairs. To test this new feature, I ran a tournament between a few of the Android UCI engines recently released on Jim Ablett's Chess Projects Website , as well as the built-in Java engine (using the fast-move setting, 32MB hash, and Nalimov, Gaviota, Scorpio, Robbobases endgame tablebases on SD card). Below the results are given in cross-table format.                   1          2          3          4          5          6  1 Stockfish 2.1.1 ********** 11110½11½1 111½111111 1111111111 1111111111 1111111111   47.5/50 2 Komodo32 1.3    00001½00½0 ********** 1111111111 1111111111 1111111111 1111111111   42.0/50 3 Rotor 0.4       000½000000 0000000000 ********** 1111011111 1111111111 1111111111   29.5/50 4 Diablo 0.5.1    0000000000 0000000000 0000100000 ********** 1111111111 1

I compiled Vladimir Medvedev's UCI engine GreKo for Android (ARM) for use in  Chess for Android  and put the binary on UCI engines for Android (with kind permission of Vladimir). Below a screenshot and the results of a few quick matches with other engines on a Nexus S (1GHz Hummingbird) with 32MB hash and Nalimov/Gaviota/Scorpio endgame tablebases on SD card. Greko 8.0 - RobboLito 0.085e4l     0.0 - 10.0  +0/-10/=0   0.00% Greko 8.0 - IvanHoe-Beta v999947c  0.5 - 9.5   +0/-9/=1    5.00% Greko 8.0 - Stockfish 2.0          1.0 - 9.0   +1/-9/=0   10.00% Greko 8.0 - Rotor 0.6a             3.0 - 7.0   +2/-6/=2   30.00% Greko 8.0 - Gaviota v0.80.0.107    5.5 - 4.5   +4/-3/=3   55.00% Greko 8.0 - GNU Chess 5.07.153.3b  6.0 - 4.0   +6/-4/=0   60.00% Greko 8.0 - RedQueen 0.9.5         6.5 - 3.5   +5/-2/=3   65.00% Greko 8.0 - BikJump v2.1P         10.0 - 0.0   +10/-0/=0 100.00% Greko 8.0 - ZCT-0.3.2500          10.0 - 0.0   +10/-0/=0 100.00%

Version 2.5.1 of Chess for Android simplifies installing third party UCI engines quite a bit. Most importantly, it is no longer required to install the Android SDK in order to push binaries to the Android device. Instead, UCI engines can simply be copied to the SD card and, from there, installed into internal memory. A few important links: Updated instructions on installing UCI engines Chess for Android manual   List of UCI engines that can be imported   A big thank you to Michel Van den Bergh for inspiring me to simplify the installation process in Chess for Android!

I have setup a webpage with  UCI engines for Android . Each entry is either a link to the engine's website, or a direct download of a binary that I compiled myself, posted with explicit permission of the engine authors. Please drop me an email if you know about other UCI engines that have been compiled "natively" for Android.

Because it is hard to print all information from the UCI engine on the phone screen, I am toying with a feature where the current move considered by the UCI engine is shown graphically. Below is a short demo of this feature. Let me know what you think!

I just released version 2.4 of Chess for Android at the Android Market with the following new feature: basic UCI engine support (ability to replace built-in Java engine with any third party UCI engine compiled "natively" for Android) Instructions on how to setup an UCI engine are given at UCI for Android . As far as I know currently only BikJump is available as stand-alone UCI engine for Android. Although stronger than the built-in engine, I hope I will be able to add links to much stronger third party UCI engines soon. Please note that support is still rather basic (elaborate setup, only tested on one engine, GUI does not support engine options, time control restricted to time-per-move, position sent as FEN, making the engine more prone to three-fold repetition, no tournaments, etc.). Nevertheless, I hope it is an interesting start.

Here is an UCI engine running on a Nexus One in Chess for Android, probing the complete 3- and 4-piece Nalimov endgame tablebases (29.6 MB) from SD card. Here is a screenshot where the UCI engine already reports a mate (using the tablebases), while the internal Java engine only reports a negative score for white given a search tree of depth 9. Steps to make this work are shown at UCI for Android .

The UCI ( Universal Chess Interface ) protocol defines an open interface between a chess engine and a graphical chess program, which allows chess programmers to focus on their engine rather than GUI details. Many programs on Windows, Linux, and MacOS support the UCI protocol (e.g. ChessBase, Arena, Sigma Chess, Lucas Chess), but as far as I know, no UCI support exists for Android. Even Chess for Android uses a simplified Java port of my own UCI engine BikJump rather than going through the UCI interface. Therefore, I am prototyping UCI support in Chess for Android with the idea that, in the long run, this will allow importing third party engines into the GUI. So far, I added a "kibitzer feature". Any UCI engine binary that has been "natively" compiled for Android (using a compiler that ships with the Android NDK ) can be imported through a file finder dialog, as shown below for a natively compiled version of BikJumpv1.8 running on the Android emulator. Once impor