A recent agadmator video pitted The Chessmaster (NES) against Stockfish 14 NNUE. What is more impressive to me is that this chess engine, released originally in 1986 and written by David Kittinger in 6502 assembly, was advertised at playing at 2000 Elo, on quite constrained hardware by today's standards. However, according to The Spacious Mind, it only plays at 1550-1600 Elo.

I am looking for calibrated Elo computer tournaments or personal experience with playing Chessmaster 2000 in gauging an accurate Elo rating. The Spacious Mind does not state how its Elo estimate for the software was derived, only that the site pitted various C64 engines against each other in a personal "2009 Commodore 64 Open Championship".

  • If someone could host that engine on Lichess as a BOT, people can play against it and eventually it would have a rating in the Lichess pool (Not a real Elo but you would get an estimate). But I don't know how to do it :)
    – Minot
    Dec 5, 2022 at 20:15
  • @Minot you would need an interface with an emulator since the original program is not based on a protocol like UCI or Xboard
    – qwr
    Dec 14, 2022 at 20:12
  • @qwr this has in fact been done, by tom7 in 2019: tom7.org/chess/weak.pdf (see chessmaster.nes_lv1 and chessmaster.nes_lv2` on pages 8-9.
    – hobbs
    Apr 4, 2023 at 6:43
  • In the days before most people had played computer chess engines, it likely players tended to learn more theory before they learn to always advoid simple errors that looking ahead 2 moves can find. Hence "never make simple error is likely to have done better in the 80s then it would now. May 10 at 10:02

2 Answers 2


The NES Chessmaster has previously faced Stockfish in the "Elo World" competition by Tom Murphy VII, presented at SIGBOVIK 2019 and on YouTube.

This is a rather unconventional tournament, to say the least. There are no human players in it, and the Elo values are uncalibrated (and probably skewed a bit by the presence of many strange/weak players). Nonetheless, NES Chessmaster and Stockfish are both in it. Stockfish 10 with a think budget of 1 million nodes and opening/endgame databases disabled receives a score of 2644 Elo; NES Chessmaster on "Level 2" receives a score of 989 Elo.

chessmaster.nes_lv2 outperforms stockfish1m_32768, a "dilution" of Stockfish that plays the same move as stockfish1m 50% of the time and plays a random legal move 50% of the time, but it underperforms stockfish1m_r16384, which plays Stockfish 75% of the time and a random move 25% of the time.

If someone were inclined to put NES Chessmaster online as a bot to collect calibrated data, as proposed by Minot in comments, a starting point might be tom7's harness, found in chessmaster.cc / chessmaster.h, and dependent on the fceulib wrapper for the FCE Ultra NES emulator.

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    – Brian Towers
    Apr 4, 2023 at 18:33

We don't know. The manufacturer believed it have been rated around 2000, but we don't know if this is correct. The computers were very slow and therefore it is impossible to know how well it really played

  • 2
    What is the logical connection between "the computers were very slow" and "it is impossible to know how well it really played"?
    – hobbs
    Apr 4, 2023 at 6:37
  • I don't know, I just asked that. @hobbs Apr 4, 2023 at 9:40

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