No matter whether I test it online on lichess or locally: Stockfish shows different variations and evaluations depending on the number of variations displayed.

Where does this behaviour come from, and how to find out SF's true objective evaluation for a position?

These images are from a locally run Stockfish 15, where it analyzed the position after 1. e4. It was interesting to watch how the different openings rise and fall in Stockfish's evaluation. For example, Stockfish considered the Ruy Lopez as the best for White against 1. ..e5, but didn't find anything against it after looking deeply enough, so it switched to the Italian, which it had thought not to be promising for an edge all the time up to depth 44. This is similar to what we see in top-level chess nowadays, the Italian game is back after a long break!

Seven variations after 1. e4 , local SF 15

However when rerunning the experiment with only 3 variations, Stockfish still tries to combat the Berlin defense. It even thinks that the Caro-Kann is the best reply against e4 and only changed mind at depth 46, where it considered 1. ..e5 the best and 1. ..c5 slightly better than the Caro-Kann.

Three variations after 1. e4, local SF 15

I have noticed the same on lichess frequently. (Side note: this isn't a question about openings; it happens in other positions as well.)

  • Please use the search function. This question has been asked and answered before.
    – Brian Towers
    Sep 8, 2022 at 13:14
  • Are you sure? I could only find two questions, that are related, but not quite the same: 22300 and 25278.
    – Hauptideal
    Sep 8, 2022 at 13:41
  • 1
    I would guess that the answer at chess.stackexchange.com/questions/25278/… would also apply here. Having to search the other moves would certainly change what's in the hashtables.
    – D M
    Sep 9, 2022 at 2:19
  • @DM that's what I assume, too. But as this is a FAQ site that also helps people who google stuff it makes sense to put an answer to this question, so that it can be found when searching for an answer online.
    – Hauptideal
    Sep 9, 2022 at 13:40


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.