TOP 20:
# PLAYER : RATING ERROR POINTS PLAYED (%) 1 Stockfish 17.1 : 3864 19 2327.0 3800 61.2% 2 Obsidian 15.09 : 3819 19 1576.0 3040 51.8% 3 PlentyChess 5.0.0 : 3803 18 1140.0 2280 50.0% 4 Alexandria 8.0.0 : 3801 20 1132.0 2280 49.6% 5 Berserk 13 : 3790 17 3824.5 7600 50.3% 6 Integral 7.0 : 3784 20 680.0 1520 44.7% 7 Horsie 1.0 : 3760 21 609.0 1520 40.1% 8 Viridithas 17.0.0 : 3759 19 627.0 1520 41.3% 9 Caissa 1.20 : 3758 17 2084.5 4177 49.9% 10 Titan 1.1 : 3742 18 1041.5 2280 45.7% 11 Clover 8.0.2 : 3739 17 1622.5 3420 47.4% 12 RubiChess 20240112 : 3727 16 1584.0 3789 41.8% 13 KomodoDragon 1.0 : 3717 19 760.0 1900 40.0% 14 Seer 2.8.0 : 3709 26 114.5 380 30.1% 15 Koivisto 9.0 : 3693 17 1673.5 3420 48.9% 16 Rebel 16.3 : 3684 23 209.0 770 27.1% 17 Slowchess 2.8 : 3609 35 219.0 340 64.4% 18 Minic 3.30 : 3501 23 659.0 1412 46.7% 19 Black Marlin 7 : 3468 20 681.0 1792 38.0% 20 Arasan 23.3 NNUE : 3467 30 129.5 340 38.1%
Updates:
Added Stockfish 17.1, Obsidian 15.09, PlentyChess 5.0.0, Alexandria 8.0.0, Integral 7.0, Viridithas 17.0.0.
Click here for the complete rating list:
The rating list – updated as of 19/04/2025 – 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).