Stefan Pohl Computer Chess

Latest Website-News (2026/10/10): Testrun of Alexandria 9.1 finished: +15 Celo to Alexandria 9.0

 

Dont forget to take a look at my EAS-Ratinglist (The world's first engine-ratinglist not measuring strength of engines, but engines's style of play). 

 

Next testrun: Gaia 4.3.3

 

Stay tuned.

UHO-Top15 Engines Ratinglist (+ regular testing of Stockfish Dev-versions)

 

 

Playing conditions:

 

The 15 strongest engines and the latest StockfishDev version are playing 1000 games vs. each opponent: 15000 games per engine are played. A RoundRobin Tournament with 120000 games overall !

 

Hardware: AMD Ryzen 9 7945HX 16-core (32 threads) notebook with 64GB RAM (since 2024/10/08), 2 identical machines. Windows 11 64bit

Speed: (singlethread, TurboBoost-mode switched off, chess starting position) Stockfish 19: 590 kn/s (when 26 games are running simultaneously)

Hash: 512MB per engine

GUI: Cutechess-cli (GUI ends game, when a 5-piece endgame is on the board, all other games are played until mate or draw by chess-rules (3fold, 50-moves, stalemate))

Tablebases: None for engines, 5 Syzygy for cutechess-cli

Openings: My UHO_2022_6mvs_+120_+129 openings are used (first 500 lines) (UHO 2022 openings are part of my Anti Draw Openings download-package). 

Ponder, Large Memory Pages & learning: Off

Thinking time: 3min+1sec per game/engine. One testrun (15000 games) takes around 80-85 hours (=3.5 days)

The version-numbers of the Stockfish engines are the date of the latest patch, which was included in the Stockfish sourcecode, not the release-date of the engine-file, written backwards (year,month,day))(example: 200807 = August, 7, 2020). The used SF compile is the AVX512-compile, which is the fastest on my AMD Ryzen CPU. SF binaries are taken from https://github.com/official-stockfish/Stockfish/releases (except the official SF-release versions, which are taken form the official Stockfish website).

Read the explanation, why I chose my testing-conditions, like I did here

 

Latest update: 2026/10/10: Alexandria 9.1 (+15 Celo to Alexandria 9.0)

 

(Ordo-calculation fixed to Stockfish 19 = 3905 Celo. Mention, there are no human or "realistic" Elo numbers in enginechess, since the engines reached superhuman strength, so I decided to use "Celo" (=Computer Elo) instead)

 

See the tournament cross-table as a picture (done by Fritz20 GUI) here

See the individual statistics of engine-results here

See the Engines Aggressiveness Score Ratinglist here

See the Gamepair-statistics of the UHO-Top15 Ratinglist here

See the Decision Time statistics of the UHO-Top15 Ratinglist here

See the full UHO Ratinglist (with EAS-Ratinglist): here

Download the current gamebase, the full-list gamebase and the archive here

See the old SPCC-Ratinglist (full list) and EAS-List from 2020 until 2023/08/28: here

 

(best Stockfish Celo: Stockfish 260930: 3912 Celo, latest full release (Stockfish 19) has 3905 Celo)

     Program                   Celo    +    - Games    Score   Av.Op. Draws

   1 Stockfish 260930        : 3912    4    4 15000    67.7%   3781   49.1%
   2 Stockfish 19 260905     : 3905    4    4 15000    66.8%   3781   48.9%
   3 Reckless 260502 a512    : 3829    4    4 15000    56.1%   3786   49.7%
   4 Torch 4d a512           : 3810    4    4 15000    53.2%   3787   49.6%
   5 PlentyChess 8.0.0       : 3805    4    4 15000    52.5%   3788   49.6%
   6 Integral 8.0 a512       : 3780    4    4 15000    48.8%   3789   49.4%
   7 Pawnocchio 2.0 a512     : 3780    4    4 15000    48.7%   3789   49.6%
   8 Coda 0.9.4 AI           : 3777    4    4 15000    48.4%   3790   49.1%
   9 Cinder 6.0 a512         : 3772    4    4 15000    47.6%   3790   49.0%
  10 Obsidian 250706 a512    : 3765    4    4 15000    46.5%   3790   48.9%
  11 Viridithas 20.0 a512    : 3758    4    4 15000    45.5%   3791   50.2%
  12 Quanticade 260929       : 3758    4    4 15000    45.4%   3791   49.4%
  13 Alexandria 9.1 a512     : 3752    4    4 15000    44.6%   3791   49.5%
  14 Triumviratus 7.0 AI     : 3752    4    4 15000    44.6%   3791   50.7%
  15 Caissa 2.0 a512         : 3736    4    4 15000    42.2%   3792   49.6%
  16 Stormphrax 8.0.0        : 3730    4    4 15000    41.3%   3793   49.0%

 

Games        : 120000 (finished)
White Wins   : 60043 (50.0%)
Black Wins   : 605    (0.5%)
Draws        : 59352 (49.5%)

Below the UHO-Top15 Ratinglist, recalculated with Gamepairs (using my Gamepair Rescoring Tool V1.5), Ordo-calculation fixed to Stockfish 17.1 = 3854 Celo, realizing Vondele's (Stockfish Maintainer) idea: "Thinking uniquely in game pairs makes sense with the biased openings used these days. While pentanomial makes  sense it is a bit complicated so we could simplify and score game pairs only (not games) as W-L-D (a traditional score of 2-0, or 1.5-0.5 is just a W)."

Mention, the errorbar here is +/-5.5 Celo (=11 overall Error), compared to +/-4 Celo in the classical ratinglist above (=1.375 wider errorbar here). But the result-gaps are (at least) 2x up to 2.5x bigger (in average), calculating with gamepairs. So, the statistical reliability of the results is much better in the Gamepair-ratinglist, compared to the classical ratinglist...

CFS means Chance For Superiority in percent, calculated by ORDO.

See the head-to-head gamepair-statistics of the UHO-Top15 Ratinglist here

   # PLAYER                  :    Celo  Error   Pairs     W     D     L   (%)  CFS(%)
   1 Stockfish 260930        :    3926     11    7500  5391  1949   160  84.9     100
   2 Stockfish 19 260905     :    3905   ----    7500  5166  2145   189  83.2     100
   3 Reckless 260502 a512    :    3707     10    7500  2902  3479  1119  61.9     100
   4 Torch 4d a512           :    3665     10    7500  2471  3517  1512  56.4     100
   5 PlentyChess 8.0.0       :    3653     10    7500  2267  3675  1558  54.7     100
   6 Integral 8.0 a512       :    3602     10    7500  1770  3608  2122  47.7      65
   7 Pawnocchio 2.0 a512     :    3600     10    7500  1738  3638  2124  47.4      90
   8 Coda 0.9.4 AI           :    3595     10    7500  1675  3662  2163  46.7     100
   9 Cinder 6.0 a512         :    3584     10    7500  1540  3707  2253  45.2     100
  10 Obsidian 250706 a512    :    3569     10    7500  1413  3650  2437  43.2     100
  11 Viridithas 20.0 a512    :    3553     10    7500  1275  3594  2631  41.0      53
  12 Quanticade 260929       :    3553     10    7500  1242  3653  2605  40.9      99
  13 Triumviratus 7.0 AI     :    3543      9    7500  1194  3550  2756  39.6      71
  14 Alexandria 9.1 a512     :    3541     10    7500  1175  3544  2781  39.3     100
  15 Caissa 2.0 a512         :    3506     10    7500   925  3355  3220  34.7     100
  16 Stormphrax 8.0.0        :    3495     10    7500   819  3348  3333  33.2     ---

 

------------------------------------------------------------------- 
--- Number of all Gamepairs          : 60000 
--- Number of drawn Gamepairs overall: 27037 (= 45.06%) 
--- Number of 1:1 drawn Gamepairs    : 13648 (= 22.75%) 
--- Number of 2-draws drawn Gamepairs: 13389 (= 22.31%) 
------------------------------------------------------------------- 

Aborted testruns, because the tested engine was too weak to enter the UHO-Top15 Ratinglist:

Icarus 1.1, Heimdall 1.5, Renegade 1.2.0, Igel 3.7.0, Minic 3.41, Booot 7.3, Black Marlin 9.0, Equisetum 1.0, Clarity 8, PZChessBot 7.1, Prune 4.0.1

Below you find a diagram of the progress of Stockfish in my tests since February 2026. 

And below that diagram, the older diagrams.

 

You can save the diagrams on your PC with mouseclick (right button) and then choose "save image"...