TOP 20:
# PLAYER : RATING ERROR POINTS PLAYED (%) 1 Stockfish 17.1 : 3859 19 2646.0 4270 62.0% 2 Obsidian 15.09 : 3814 19 1807.0 3420 52.8% 3 Lc0 0.31.2 BT3-7464000 1650m : 3799 36 95.5 180 53.1% 4 PlentyChess 5.0.0 : 3798 19 1140.0 2280 50.0% 5 Alexandria 8.0.0 : 3796 20 1354.0 2660 50.9% 6 Berserk 13 : 3785 18 4070.5 8040 50.6% 7 Integral 7.0 : 3779 21 893.0 1900 47.0% 8 Horsie 1.0 : 3754 24 609.0 1520 40.1% 9 Viridithas 17.0.0 : 3754 22 627.0 1520 41.3% 10 Caissa 1.20 : 3752 18 2084.5 4177 49.9% 11 RubiChess 20240817 : 3737 19 1145.0 2660 43.0% 12 Titan 1.1 : 3736 18 1041.5 2280 45.7% 13 Clover 8.0.2 : 3733 20 1622.5 3420 47.4% 14 KomodoDragon 1.0 : 3711 19 760.0 1900 40.0% 15 Seer 2.8.0 : 3694 22 277.5 760 36.5% 16 Koivisto 9.0 : 3685 16 1742.0 3540 49.2% 17 Rebel 16.3 : 3678 22 209.0 770 27.1% 18 Slowchess 2.8 : 3604 32 219.0 340 64.4% 19 Minic 3.30 : 3495 20 659.0 1412 46.7% 20 Black Marlin 7 : 3462 20 681.0 1792 38.0%
Updates:
Added Lc0 0.31.2 BT3-7464000 tested on a NVIDIA 1650m GPU, Lc0 0.31.2 BT3-7464000 1650m on a CPU, and RubiChess 20240817.
Click here for the complete rating list:
The rating list – updated as of 05/04/2025 – is calculated with Ordo and was obtained under the following assumptions.
- The Elo rating of Rebel 6 UCI (1994) is fixed at 2450 points, which serves as an “anchor” for all others. This score is the average value of the results obtained by the original version of the engine in various matches against human GMs in the early 90s, derived from various official or unofficial sources (Talkchess.com, Rebel13.nl, computerchessuk.com, various forums…).
- Compared to the previous version of the rating list, the second anchor, Fritz Brains in Bahrain (emulated from Deep Fritz 8), has been removed, as it distorted the true value of the engines too much.
- Several electronic chessboards have been added whose strength in terms of Elo obtained through matches with humans is fairly well known. In this way, the rating list should provide engine scores that are more easily comparable with human ones. The electronic chessboards were emulated with CB-Emu, and made to play against several UCI and Winboard engines of similar strength.
- The time per game was set to 40/120′ repeated, reparameterized to the processing speed of a Pentium 90. The execution speed of the latter was emulated, and through various benchmarks done in the past on real P90 machines, I tried to obtain a value as close as possible to reality. Consequently, on modern PCs the actual time per game was 40/125” or 40/130” (seconds) depending on the PC used for the test, comparable to other blitz tests found on the net. For some engines, such as Chess Titans, it was not possible to define a game time; for this reason, I have indicated the characteristics of the CPU on which it was tested.
- The opening suite consists of 190 different positions, repeated for each engine (each engine played the same opening both as white and black). For older engines, not equipped with a UCI or XBoard interface (such as the 1988 version of BattleChess), I manually reproduced the various moves suggested by the programs. Also for these engines, as for all the others, the playing time was reparameterized to the performance of a Pentium 90. For this reason, the games of these engines are few compared to the total, and based on random selections of the 190 openings. The opening suite can be downloaded here.
- All the chess engines used are freely available on the net, with the exception of commercial programs that I purchased years ago, and are limited to using only one CPU core.
- In the “Top 10”, I have not included past versions of Stockfish, nor engines derived from it (such as Shashchess). In the complete rating list, I have also included past versions of Stockfish for comparison.
- The main goal of this rating list, made for my exclusive enjoyment, was both to determine the playing level of modern engines compared to past ones, but also to evaluate the actual playing strength of many programs that I loved in my youth (the aforementioned Battlechess, for example).