Aart's Blog

I just released version 2.9.4 for Chess for Android, available from the Android market or as direct download . This version introduces the much requested "infinite analysis" mode for an imported UCI engine, in which the engine reports its analysis of positions without actually making moves. To enable this mode, change the level to free play, as shown in the following screenshots. If an UCI engine is imported, its analysis of the current position will appear below the board. The user can freely play through previous games or make new moves. When at the end of a game still in progress, pressing the ">" button will play the best move found by the UCI engine. Changing the level, or unloading the UCI engine will exit the "infinite analysis" mode. Although the feature may seem simple, it was actually far from straightforward to implement, also because not all UCI engines behave the same for the "go infinite" command. Please let me know if yo

Lucas added the  movetime command to DoubleCheck (the stop command is still lacking) which enabled conducting a few quick 1-second per move matches to determine the strength of the engine. DoubleCheck 1.1 - Komodo32 2.03 AB  +0/-10/=0  0.00% - GreKo 8.0         +0/-10/=0  0.00% - gaviota v0.83.0.3 +0/-9/=1   5.00% - RedQueen 0.9.8    +0/-9/=1   5.00% - Jazz v444 JA      +1/-7/=2  20.00% - BikJump v2.1P     +2/-4/=4  40.00% - ZCT-0.3.2500      +4/-5/=1  45.00% - Chess for Android +6/-0/=4  80.00%

I compiled Lucas Braesch's DoubleCheck 1.1 for Android (ARM) and put it on the UCI Engines for Android website . The engine works reasonably well in Chess for Android. However, because the UCI command movetime is not implemented yet, it plays almost instantaneously, making matches to determine its strength less useful at the moment.

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