[cfreksen]

To elaborate, in the Top Chess Engine Championship (which is also used as a benchmark in the AlphaZero vs Stockfish comparison) Stockfish has won all seasons since May 2020[1,2]. A common runner up for those seasons is LCZero[3], which is an engine that is derived from/a reimplementation of AlphaZero. Stockfish is also ahead of LCZero in Fischer random chess (as hosted at TCEC) winning 4 out of the 5 FRC tournaments.

As for how close Stockfish 8 is to a current version of Stockfish, Stockfish 15 has ~400 more ELO than Stockfish 8 as measured in their own self-tests[4].

However, when making these comparisons between AlphaZero and Stockfish it might be tempting to frame it as machine-learning-engine vs classical-engine, which is not true. Stockfish incorporates a neural network when evaluating chess positions[5].

[1]: https://en.wikipedia.org/wiki/Top_Chess_Engine_Championship#...

[2]: https://en.wikipedia.org/wiki/Stockfish_(chess)#Top_Chess_En...

[3]: https://en.wikipedia.org/wiki/Leela_Chess_Zero

[4]: https://github.com/glinscott/fishtest/wiki/Regression-Tests#...

[5]: https://stockfishchess.org/blog/2020/introducing-nnue-evalua...

[pvitz]

Great summary! Also, at [1], one can hear Deepmind hinting at that state-of-the-art engines (Stockfish, Leela Chess Zero) will beat Alphazero.

[1] https://www.youtube.com/watch?v=N2MncpRMnFA&feature=youtu.be...