Since you’re here...

... we have a small favour to ask. More people, like you, are reading and supporting our blog: "Chess Engines Diary". And unlike many other sites and blogs, we made the choice to keep our articles open for all, regardless of where they live or what they can afford to pay.

We hope you will consider supporting us today. We need your support to continue to exist, because good entries are more and more work time. Every reader contribution, however big or small, is so valuable. Support "Chess Engines Diary" even a small amount– and it only takes a minute. Thank you.

============================== My email: jotes@go2.pl



Chess engine: Stockfish 20011003



Stockfish - UCI chess engine, compiled by Joost VandeVondele

Update Elo estimates for terms in search

This updates estimates from 1.5 year ago, and adds missing terms. All estimates from tests run on fishtest at 10+0.1 (STC), 20000 games, error bars +- 3 Elo, see the original message in the pull request for the full list of tests.
Noteworthy changes are step 7 (futility pruning) going from ~30 to ~50 Elo and step 13 (pruning at shallow depth) going from ~170 to ~200 Elo.

@Rocky640 made the suggestion to look at time control dependence of these terms. I picked two large terms (early futility pruning and singular extension), so with small relative error. It turns out it is actually quite interesting (see figure 1).
Contrary to my expectation, the Elo gain for early futility pruning is pretty time control sensitive, while singular extension gain is not.

Going back to the old measurement of futility pruning (30 Elo vs today 50 Elo), the code is actually identical but the margins have changed. It seems like a nice example of how connected terms in search really are, i.e. the value of early futility pruning increased significantly due to changes elsewhere in search.

No functional change.


Rating JCER=3344

Stockfish 20011003 - download


Comments

Popular posts from this blog

New version chess engine: Lc0 BT4

Killfish 071223 wins Strong Engines Tournament (Tests by Jörn Gronemann, Heide, 2024.02.26)

New chess engine: HypnoS 190324 (derived from Stockfish)

SF-PRO 23.02.2024 wins Strong Engines Tournament (Tests by Jörn Gronemann, Heide, 2024.03.01)

INCOGNITO 7 and Killfish 130324 wins Strong Engines Tournament (Tests by Jörn Gronemann, Heide, 2024.03.15)

SF-PRO 08.03.2024 wins New Engines Test, 09-10.03.2024

Chess engine: SF 16.1 MPV